ELECTROPHORESIS, Issue 22 2009
Jurim Gwon
Abstract Cellulose dimethylphenylcarbamate (CDMPC)-immobilized zirconia (CDMPCZ) was used as a chiral stationary phase for enantioseparation of a set of nine racemic compounds in reversed-phase CEC. Influences of the type and composition of organic modifier and the applied voltage on enantioseparation were examined. Separation data on CDMPCZ were also compared with those on CDMPC-immobilized silica (CDMPCS). Enantiomers of the analytes investigated are well separated in ACN/phosphate buffer mobile phases. Better enantioselectivity and resolution were obtained with ACN than MeOH as the organic modifier. Retention was longer but better enantioselectivity and resolution were obtained on CDMPCZ than CDMPCS. [source]

Metabolic responses of novel cellulolytic and saccharolytic agricultural soil Bacteria to oxygen

ENVIRONMENTAL MICROBIOLOGY, Issue 4 2010
Stefanie Schellenberger
Summary Cellulose is the most abundant biopolymer in terrestrial ecosystems and is degraded by microbial communities in soils. However, relatively little is known about the diversity and function of soil prokaryotes that might participate in the overall degradation of this biopolymer. The active cellulolytic and saccharolytic Bacteria in an agricultural soil were evaluated by 16S rRNA 13C-based stable isotope probing. Cellulose, cellobiose and glucose were mineralized under oxic conditions in soil slurries to carbon dioxide. Under anoxic conditions, these substrates were converted primarily to acetate, butyrate, carbon dioxide, hydrogen and traces of propionate and iso-butyrate; the production of these fermentation end-products was concomitant with the apparent reduction of iron(III). [13C]-cellulose was mainly degraded under oxic conditions by novel family-level taxa of the Bacteroidetes and Chloroflexi, and a known family-level taxon of Planctomycetes, whereas degradation under anoxic conditions was facilitated by the Kineosporiaceae (Actinobacteria) and cluster III Clostridiaceae and novel clusters within Bacteroidetes. Active aerobic sub-communities in oxic [13C]-cellobiose and [13C]-glucose treatments were dominated by Intrasporangiaceae and Micrococcaceae (Actinobacteria) whereas active cluster I Clostridiaceae (Firmicutes) were prevalent in anoxic treatments. A very large number (i.e. 28) of the detected taxa did not closely affiliate with known families, and active Archaea were not detected in any of the treatments. These collective findings suggest that: (i) a large uncultured diversity of soil Bacteria was involved in the utilization of cellulose and products of its hydrolysis, (ii) the active saccharolytic community differed phylogenetically from the active cellulolytic community, (iii) oxygen availability impacted differentially on the activity of taxa and (iv) different redox guilds (e.g. fermenters and iron reducers) compete or interact during cellulose degradation in aerated soils. [source]

In vivo Performance of Osteoactivated Cellulose-Based Scaffolds in Bony Critical-Size Defects,

ADVANCED ENGINEERING MATERIALS, Issue 8 2009
Sabine Ponader
Cellulose-based scaffolds osteoactivated with different sodium silicate coatings (pure and bisphosphonate or strontium enriched respectively) can serve as long-term depots for a slow drug-release. Thus they are a promising and cost-saving alternative to the short-lived drug delivery systems of recombinant bone promoting proteins. [source]

Does leaf quality mediate the stimulation of leaf breakdown by phosphorus in Neotropical streams?

FRESHWATER BIOLOGY, Issue 4 2006
MARCELO ARDÓN
Summary 1. Lowland tropical streams have a chemically diverse detrital resource base, where leaf quality could potentially alter the effect of high nutrient concentrations on leaf breakdown. This has important implications given the extent and magnitude of anthropogenic nutrient loading to the environment. 2. Here, we examine if leaf quality (as determined by concentrations of cellulose, lignin and tannins) mediates the effects of high ambient phosphorus (P) concentration on leaf breakdown in streams of lowland Costa Rica. We hypothesised that P would have a stronger effect on microbial and insect processing of high- than of low-quality leaves. 3. We selected three species that represented extremes of quality as measured in leaves of eight common riparian species. Species selected were, from high- to low-quality: Trema integerrima > Castilla elastica > Zygia longifolia. We incubated single-species leaf packs in five streams that had natural differences in ambient P concentration (10,140 ,g soluble reactive phosphorus (SRP) L,1), because of variable inputs of solute-rich groundwater and also in a stream that was experimentally enriched with P (approximately 200 ,g SRP L,1). 4. The breakdown rate of all three species varied among the six streams: T. integerrima (k -values range: 0.0451,0.129 day,1); C. elastica (k -values range: 0.0064,0.021 day,1); and Z. longifolia (k -values range: 0.002,0.008 day,1). Both ambient P concentration and flow velocity had significant effects on the breakdown rate of the three species. 5. Results supported our initial hypothesis that litter quality mediates the effect of high ambient P concentration on leaf processing by microbes and insects. The response of microbial respiration, fungal biomass and invertebrate density to high ambient P concentration was greater in Trema (high quality) than in Castilla or Zygia (low quality). Variation in flow velocity, however, confounded our ability to determine the magnitude of stimulation of breakdown rate by P. 6. Cellulose and lignin appeared to be the most important factors in determining the magnitude of P-stimulation. Surprisingly, leaf secondary compounds did not have an effect. This contradicts predictions made by other researchers, regarding the key role of plant secondary compounds in affecting leaf breakdown in tropical streams. [source]

Creating Hierarchical Structures in Renewable Composites by Attaching Bacterial Cellulose onto Sisal Fibers,

ADVANCED MATERIALS, Issue 16 2008
Julasak Juntaro
The growth of bacterial-cellulose nanofibrils on the surfaces of micrometer-scale natural fibers provides a route to a new class of hierarchical, renewable, degradable composites. The nanofibrils improve the interaction between the primary fibers and the matrix, leading to improved mechanical properties and water resistance. [source]

Cellulose as a renewable resource for the synthesis of wood consolidants

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
Giacomo Cipriani
Abstract Crosslinkable cellulose ethers as allyl cellulose, allyl carboxymethyl cellulose, and allyl n -hydroxypropyl cellulose were synthesized and characterized, and their use as consolidating agents for waterlogged wood was studied. For this kind of application, structural properties similar to those of wood's polysaccharide components are desired in the design stage of new consolidants. The choice to synthesize cellulose ethers was determined from the possibility of using cellulose as the starting material because of its large availability in nature, biocompatibility, and low cost. In addition, cellulose ethers are quite easy to obtain, and they can have different properties, depending on the nature and the amount of the functional groups introduced. For this purpose, a cellulose with a lower degree of polymerization was also used for the synthesis of related cellulose ethers. By means of Fourier transform infrared spectroscopy, the affinity of the cellulose derivatives for degraded lignin flours was detected. The preliminary results of this study show that these polysaccharide compounds may be proposed as wood consolidating agents. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Catalytic performance of cellulose supported palladium complex for Heck reaction in water

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Ying Xu
Abstract Cellulose supported palladium complex was synthesized and characterized by XPS, TG/DTA etc. The complex was found to be an efficient catalyst for Heck reaction of acrylic acid or styrene with aryl iodides at low temperature in water under atmospheric condition, the substituted trans -cinnamic acid or 1,2-stilbene was obtained in stereoselectivity. Repeated tests showed that the catalyst have good reusability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Separation and recovery of cellulose and lignin using ionic liquids: a process for recovery from paper-based waste

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2009
Huma Lateef
Abstract BACKGROUND: The production of paper makes use of cellulose and lignin as a raw material, and almost all cellulose and lignin production comes from raw wood materials, contributing to deforestation and resulting in potential environmental harm. It is therefore beneficial to develop technologies for cellulose and lignin recovery for re-use and sustainability of resources. RESULTS: Three imidazolium based ionic liquids (ILs), 1-(2-cyanoethyl)-3-methylimidazolium bromide (cyanoMIMBr), 1-propyl-3-methylimidazolium bromide (propylMIMBr) and 1-butyl-3-methylimidazolium chloride (butylMIMCl), were synthesised by microwave technology and fully characterised by mass spectrometry, thermogravimetric differential scanning calorimetry, thin layer chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopies. Cellulose and lignin were soluble in all three ILs with solubility being greatest in cyanoMIMBr. Regeneration of cellulose and lignin was achieved from saturated solutions of cellulose in IL and lignin in IL for all three ILs. The ILs propylMIMBr and butylMIMBr have been used for the first time in the separation and recovery of cellulose and lignin and regeneration of the IL from a mixture of cellulose and lignin in IL. FTIR analysis confirms successful recovery. CONCLUSIONS: This work demonstrates the ability of ILs to separate and recover cellulose and lignin from a mixed system. Copyright © 2009 Society of Chemical Industry [source]

A modified cellulose adsorbent for the removal of nickel(II) from aqueous solutions

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2006
David W O'Connell
Abstract A series of adsorption studies was carried out on a glycidyl methacrylate- modified cellulose material functionalised with imidazole (Cellulose- g -GMA-Imidazole) to assess its capacity in the removal of Ni(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Ni(II) from solution by the Cellulose- g -GMA-Imidazole. In particular, the influence of initial metal concentration, contact time, solution temperature and pH were assessed. The studies indicated a Ni(II) uptake on the Cellulose- g -GMA-Imidazole sorbent of approximately 48 mg g,1 of nickel from aqueous solution. The adsorption process fitted the Langmuir model of adsorption and the binding process was mildly endothermic. The kinetics of the adsorption process indicated that nickel uptake occurred within 400 min and that pseudo-second order kinetics best describe the overall adsorption process. Nickel(II) adsorption, recovery and re-adsorption studies indicated that at highly acidic pH values the adsorbent material becomes unstable, but in the range pH 3,6, the adsorbent is stable and shows limited but significant Ni(II) recovery and re-adsorption capability. Copyright © 2006 Society of Chemical Industry [source]

Extraction and Application of Dietary Fiber and Cellulose from Pineapple Cores

JOURNAL OF FOOD SCIENCE, Issue 4 2002
T. Prakongpan
Pineapple core dietary fiber (PDF) was obtained by alcoholic extraction; pineapple core cellulose (PC) was a product of alkali extraction with a bleaching process. Total dietary fiber content of PDF and PC was 99.8% and 95.2% (dry basis), respectively, and their water activity was 0.25. PC contained 91.2% cellulose with a pH value of 4.0, while that of PDF was 6.2. The fiber product with large particle size gave higher values than the product with smaller particles for pH, water and oil retention capacity, settling volume and emulsifying activity. Both had rough, pitted surfaces and presented showed good functions in cake-type doughnuts, golden layer cake and beef burgers. [source]

Ultrastructural and Cytochemical Studies on Cellulose, Xylan and Pectin Degradation in Wheat Spikes Infected by Fusarium culmorum

JOURNAL OF PHYTOPATHOLOGY, Issue 5 2000
Z. Kang
The cell wall components cellulose, xylan and pectin in different tissues of noninoculated healthy and Fusarium culmorum (W. G. Smith) Sacc-infected wheat spikes were localized by means of enzyme-gold and immuno-gold labelling techniques. The cell walls in the ovary, lemma and rachis of the healthy wheat spike showed labellings in different patterns and densities with cellulase-gold and xylanase-gold probes, as well as with the antipectin monoclonal antibody JIM7. The inter- and intracellular growth of the pathogen in the ovary, lemma and rachis of the infected wheat spike, not only caused pronounced alterations of cell walls and middle lamella matrices, but also led to marked modifications of cell wall components. The enzyme-gold and immuno-gold labellings in the infected host tissues revealed that the labelling densities for cellulose, xylan and pectin were significantly reduced in the cell walls of infected ovary, lemma and rachis as compared with corresponding healthy host tissues. The host cell walls in contact with or close to hyphae of the pathogen showed more marked morphological changes and much greater reduction of the labelling density than those in distance from the hyphae. These results provide evidence that F. culmorum may produce cell-wall-degrading enzymes such as cellulases, xylanases and pectinases during infection and colonization of wheat spikes tissues. Furthermore, at the early stage of infection (e.g. 3 days after inoculation), the degradation of pectin was greater than that of cellulose and xylan in the cell walls of the same infected host tissues, indirectly suggesting that the pectinases may be secreted earlier or exert higher activities than cellulases and xylanases. Zusammenfassung Die Zellwandkomponenten Zellulose, Xylan und Pektin in verschiedenen Geweben von nicht inokulierten gesunden und Fusarium culmorum (W. G. Smith) Sacc. infizierten Weizenähren wurden mit Hilfe von Enzym-Gold- und Immun-Gold-Markierungstechniken nachgewiesen. Die Zellwände des Fruchtknotens der gesunden Ähre wiesen unterschiedliche Markierungsmuster und -dichten mit Zellulase-Gold- und Xylanase-Gold-Proben sowie mit dem monoklonalen Anti-Pektin Antikörper JIM7 auf. Das inter-und intrazelluläre Wachstum des Pathogens im Fruchtknoten, in der Deckspelze und Spindel der infizierten Ähre verursachte nicht nur ausgeprägte Veränderungen der Zellwände und der Matrix der Mittellamelle sondern führte auch zu deutlichen Modifikationen der Zellwandkomponenten. Die Enzym-Gold- und die Immun-Gold-Markierungen in den infizierten Wirtsgeweben ergaben deutlich verminderte Markierungsdichten für Zellulose, Xylan und Pektin in den Zellwänden des infizierten Fruchtknotens, der Deckspelze und Spindel im Vergleich zum entsprechenden gesunden Wirtsgewebe. Wirtszellwände, die sich in Kontakt mit den Hyphen oder in der Nähe der Hyphen des Pathogens befanden, zeigten deutlichere morphologische Veränderungen und stärkere Reduktionen der Markierungsdichten als die, die entfernt von Hyphen waren. Diese Ergebnisse weisen darauf hin, da,F. culmorum zellwandabbauende Enzyme wie Zellulasen, Xylanasen und Pektinasen während der Infektion und Besiedlung der Gewebe von Weizenähren ausscheidet. Au,ierdem war im frühen Infektionsstadium (z. B. 3 Tage nach Inokulation) der Abbau von Pektin stärker als der von Zellulose und Xylan in den Zellwänden infizierter Wirtsgewebe. Dies deutet darauf hin, da, Pektinasen früher ausgeschieden werden oder stärkere Aktivität als Zellulasen und Xylanasen besitzen. [source]

Effects of glucose, cellulose, and humic acids on soil microbial eco-physiology

JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2004
Oliver Dilly
Abstract Microbial eco-physiology in soils is regulated by substrate quality of the organic matter. This regulation was studied for a forest and an agricultural soil by the combination of activity and biomass techniques. Soil respiration was stimulated by the substrate quality in the order, humic acid < cellulose < glucose over 20 days. Concurrently, substrate addition increased the respiratory quotient (RQ), defined as the ratio of mol CO2 evolution per mol O2 uptake. Anabolic processes were mainly induced by glucose addition. Soil preconditioned with glucose showed a decrease in the RQ value during glucose-induced microbial growth in comparison to non-amended control. The decrease in the RQ value induced by preconditioning with cellulose and humic acid was lower. Glucose, cellulose, and humic acid addition modified the microbial biomass as estimated by fumigation-extraction (FE), substrate-induced respiration (SIR), and ATP content. Since each biomass estimate refers to specific microbial components, shifts in microbial eco-physiology and community structure induced by substrate quality were reflected by SIR : FE and SIR : ATP ratios. The active and glucose-responsive biomass in the forest soil which was earlier suggested as being dominated by K-strategists was increased in the order, humic acid < cellulose < glucose. Einfluss von Zugaben von Glucose-, Cellulose und Huminsäuren auf die mikrobielle Ökophysiologie im Boden Die Ökophysiologie der mikrobiellen Gemeinschaften in Böden ist abhängig von der Substratqualität der organischen Substanz. Dies wurde nach Zugabe von Substraten für zwei Böden, einer unter Buchenwald und einer unter Acker, anhand einer Kombination von biochemischen und physiologischen Aktivitäts- und Biomassetechniken analysiert. Die Substratzugabe erhöhte die Bodenatmung über 20 Tage hinweg in der Reihenfolge Huminsäuren < Cellulose < Glucose. Gleichzeitig wurde auch der respiratorische Quotient (RQ), definiert als das Verhältnis von CO2 -Freisetzung zu O2 -Aufnahme, durch die Substratzugabe erhöht und anabolische Prozesse induziert. Das mikrobielle Wachstum wurde in erster Linie durch Glucose stimuliert. Der mit Glucose als Substrat versetzte Boden zeigte eine Abnahme des RQ während eines glucose-induzierten Wachstums im Vergleich zur Kontrolle. Eine solche Abnahme war bei der Huminsäure- und Cellulosebehandlung geringer. Die Zugabe von Glucose, Cellulose und Huminsäuren veränderte schließlich die mikrobielle Biomasse, welche mittels Fumigation-Extraktion, substratinduzierter Atmung und ATP-Gehalt ermittelt wurde. Da jede Technik spezifische mikrobielle Komponenten erfasst, wurden Veränderungen in der mikrobiellen Ökophysiologie und der Struktur der mikrobiellen Gemeinschaften durch die Substrate induziert, die in dem SIR:FE- und SIR:ATP-Verhältnis erkennbar waren. Die aktive und glucoseaktivierbare Biomasse in einem von K-Strategen dominierten Waldboden nahm von Huminsäure-, über Cellulose- und Glucosezugabe hin zu. [source]

Properties and Bioapplications of Blended Cellulose and Corn Protein Films

MACROMOLECULAR BIOSCIENCE, Issue 9 2009
Quanling Yang
Abstract A series of blend films have been prepared from cellulose and corn protein in a NaOH/urea solution by a simple, low cost, and ,green' pathway. Their structure and properties are characterized by amino acid analysis, X-ray diffraction, scanning electron microscopy, thermogravimetry, and tensile testing. The results reveal that a certain miscibility exists between cellulose and corn protein and their thermal stability and mechanical properties are improved significantly, compared with the protein materials, when the protein content is less than 18 wt.-%. The protein, which contains tyrosine and histidine, could remain in the blend films after being washed for ten days, which indicates the strong hydrogen bonding between the hydroxy groups of cellulose and the hydroxyphenyl of tyrosine and imidazolyl of histidine in the protein. Furthermore, they exhibit good biocompatibility capable of supporting cell adhesion and proliferation. [source]

Fractionation of Methyl Cellulose According to Polarity , a Tool to Differentiate First and Second Order Heterogeneity of the Substituent Distribution

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 11 2006
Roland Adden
Abstract Summary: A set of four MCs (DS 1.80,1.95) has been analyzed with regard to their substituent pattern in the glucosyl units and along the polymer chain. The average heterogeneity of methylation observed for the entire material was analyzed in more detail after fractionation according to polarity. All fractions obtained were analyzed with respect to their DS, monomer composition and deviation from a random distribution of these monomers in the polymer chains. By this approach, heterogeneity of first and second order could be differentiated. While for three of the MCs only a minor DS-gradient over the material was observed, a more pronounced heterogeneity of first order was obtained for MC 4. ESI mass spectrum of the undissolved residue of MC 2 after deuteromethylation and partial hydrolysis; DP 2 and 3 are shown in detail. Signals are assigned according to the number of CH3 -groups. [source]

Structure and Properties of CdS/Regenerated Cellulose Nanocomposites

MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2005
Dong Ruan
Abstract Summary: Novel inorganic-organic hybrid materials composed of cadmium sulfide (CdS) semiconducting nanocrystals and regenerated cellulose (RC) were prepared by using in situ synthesizing method. Cellulose was dissolved in a 6 wt.-% NaOH/4 wt.-% urea/thiourea aqueous solution at low temperature followed by addition of cadmium chloride (CdCl2), resulting that the CdS nanocrystals were successfully grown in situ in the cellulose solution. Nanocomposite films containing homogeneous CdS nanoparticles were obtained by casting the resulting solution. Their structure and optical properties were characterized by X-ray photoelectron spectroscopy, wide-angle X-ray diffraction, thermogravimetry analysis, dynamic mechanical analysis, atomic force microscopy, transmittance electronic microscope, UV-vis spectroscopy, and photoluminescence spectroscopy. The experimental results confirmed that the CdS nanocrystalline existed in the composite films, and cellulose matrix provided a confined medium for CdS particle growth in uniform size. The CdS/RC composites showed narrow emission in photoluminescence spectra, and their optical absorbance in the UV range was higher than that of the cellulose film without CdS. This work provided a simple method to prepare cellulose functional materials in NaOH/urea aqueous solution. Photoluminescence of CdS/RC nanocomposites and TEM image of CdS nanocrystals dispersed in RC matrix. [source]

Noble Metal Decoration and Alignment of Carbon Nanotubes in Carboxymethyl Cellulose

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 2 2008
Mallikarjuna N. Nadagouda
Abstract A facile microwave method (MW) is described that accomplishes alignment and decoration of noble metals on carbon nanotubes (CNT) wrapped with carboxymethyl cellulose (CMC). Carbon nanotubes such as single- and multi-walled, and Buckminsterfullerene (C-60) are well dispersed using the sodium salt of CMC under sonication. Addition of respective noble metal salts then generates noble metal-decorated CNT composites at room temperature. However, aligned nanocomposites of CNTs could only be generated by exposing the above nanocomposites to MW irradiation. The CNT composites are characterized using scanning electron microscopy, energy dispersive X-ray analysis, X-ray mapping, transmission electron microscopy, and UV-visible spectroscopy. The general preparative procedure is versatile and provides a simple route to manufacturing useful metal-coated CNT nanocomposites. [source]

Efficient Homogeneous Chemical Modification of Bacterial Cellulose in the Ionic Liquid 1- N -Butyl-3-methylimidazolium Chloride

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 19 2006
Kerstin Schlufter
Abstract Summary: Bacterial cellulose (BC), a unique type of cellulose, with high degree of polymerization of 6,500 could be dissolved easily in the ionic liquid 1- N -butyl-3-methylimidazolium chloride. For the first time, well-soluble BC acetates and carbanilates of high degree of substitution (up to a complete modification of all hydroxyl groups) were accessible under homogeneous and mild reaction conditions. Characterization of the new BC derivatives by NMR and FTIR spectroscopy shows an unexpected distribution of the acetyl moieties in the order O-6,>,O-3,>,O-2. 13C NMR spectrum (DMSO- d6) of a cellulose acetate with a DS of 2.25 synthesized in 1- N -butyl-3-methylimidazolium chloride. [source]

Regioselective Dendritic Functionalization of Cellulose

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2004
Mohammad L. Hassan
Abstract Summary: A series of regioselectively dendronized cellulose derivatives has been prepared by the treatment of cellulose in a N,N -dimethylacetamide/LiCl solvent system with dendrons possessing isocyanate focal substituents. These new materials were characterized using FT-IR and 13C NMR spectroscopies, and thermogravimetric analysis; the products were highly soluble in a wide range of organic solvents. Substitution pattern of the dendronized cellulose. [source]

Illumination of Cellulose with Linearly Polarized Visible Light

MACROMOLECULAR SYMPOSIA, Issue 1 2008
A. Konieczna - Molenda
Abstract Summary: Aqueous suspensions of cellulose of long polysaccharide chains, were illuminated with visible polarized light (VPL) for 20 and 50 hrs. Crystal structure, thermal properties with Differential Scanning Calorimetry (DSC) and degree of polymerization (DP) of the samples were determined. Additionally, kinetic of enzymatic as well as acid-catalyzed hydrolysis of cellulose was estimated. Illumination of cellulose with VPL for 50 hrs increased its DP by 15%. X-ray diffraction patterns revealed that the illumination resulted in an increase in the amount of cellulose crystalline phase. The DSC measurements indicated differences in the water molecules distribution depending on the sample treatment confirming an increase in the crystallinity of the illuminated cellulose. After prolonged illumination, cellulose was resistant to oxidation and had lower susceptibility to enzymatic and acid-catalyzed hydrolysis. [source]

Application of a Library of Artificial Receptors Formed by Self-Organization of N -Lipidated Peptides Immobilized on Cellulose for Preliminary Studies of Binding of N -Phenylpiperazines

MOLECULAR INFORMATICS, Issue 6-7 2009
Justyna Fraczyk
Abstract A library of artificial receptors formed by self-organization of N -lipidated peptides attached to cellulose via aminophenylamino-1,3,5-triazine was synthesized and used for docking small, colorless guests. Interactions of colorless guest with receptors were visualized by using competitive adsorption-desorption of appropriate reporter dye. Analysis of binding pattern of N -phenylpiperazine derivatives with gradually increased lipophilicity was found diagnostic for structural changes of guest molecules. Several library members demonstrated attributes characteristic for detection of alteration of lipophilicity of the guest structure. [source]

Synthesis and NMR characterization of 6-Phenyl-6-deoxy-2,3-di- O -methylcellulose,

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2002
Dr Navzer (Nozar) D. Sachinvala
Abstract Cellulose (1) was converted for the first time to 6-phenyl-6-deoxy-2,3-di- O -methylcellulose (6) in 33% overall yield. Intermediates in the five-step conversion of 1 to6 were: 6- O -tritylcellulose (2), 6- O -trityl-2,3-di- O -methylcellulose (3), 2,3-di- O -methylcellulose (4); and 6-bromo-6-deoxy-2,3-di- O -methylcellulose (5). Elemental and quantitative carbon-13 analyses were concurrently used to verify and confirm the degrees of substitution in each new polymer. Gel permeation chromotography (GPC) data were generated to monitor the changes in molecular weight (DPw) as the synthesis progressed, and the compound average decrease in cellulose DPw was , 27%. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the decomposition of all polymers. The degradation temperatures (,°C) and percent char at 500,°C of cellulose derivatives 2 to 6 were 308.6 and 6.3%, 227.6,°C and 9.7%, 273.9,°C and 30.2%, 200.4,°C and 25.6%, and 207.2,°C and 27.0%, respectively. The glass transition temperature (Tg) of6- O -tritylcellulose by dynamic mechanical analysis (DMA) occurred at 126.7,°C and the modulus (E,, Pa) dropped 8.9 fold in the transition from ,150,°C to,+,180,°C (6.6,×,109 to 7.4,×,108 Pa). Modulus at 20,°C was 3.26,×,109 Pa. Complete proton and carbon-13 chemical shift assignments of the repeating unit of the title polymer were made by a combination of the HMQC and COSY NMR methods. Ultimate non-destructive proof of carbon,carbon bond formation at C6 of the anhydroglucose moiety was established by generating correlations between resonances of CH26 (anhydroglucose) and C1,, H2,, and H6, of the attached aryl ring using the heteronuclear multiple-bond correlation (HMBC) method. In this study, we achieved three major objectives: (a) new methodologies for the chemical modification of cellulose were developed; (b) new cellulose derivatives were designed, prepared and characterized; (c) unequivocal structural proof for carbon,carbon bond formation with cellulose was derived non-destructively by use of one- and two-dimensional NMR methods. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Carbon isotope determination for separate components of heterogeneous materials using coupled thermogravimetric analysis/isotope ratio mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2008
David A. C. Manning
A gas-tight thermal analysis system (Netzsch STA 449C Jupiter) has been connected to an isotope ratio mass spectrometer (PDZ Europa 20-20) via an interface containing an oxidizing furnace, water trap, and gas-sampling valve. Using this system, ,13C has been measured for CO2 derived from the thermal decomposition of carbonate and oxalate minerals and organic materials at temperatures that correspond to different decomposition events. There is close agreement between measured and published ,13C values for carbonate and oxalate minerals, which have simple decarbonation reactions on heating. Cellulose and lignin-rich materials show much more complex thermal decomposition, reflecting differences in their purity and structure, and measured ,13C values vary with the temperature of gas sampling. Provided that measurements are made at temperatures that correspond to the decomposition of cellulose and lignin (indicated by maximum weight loss), internally consistent data can be obtained. However, measurements for cellulose and lignin are systematically enriched in ,13C (by up to 1.4,) with respect to those reported for reference materials, possibly due to the slower combustion kinetics (compared with EA-IRMS). Thermogravimetric analysis/isotope ratio mass spectrometry (TG-IRMS) is ideal for materials and samples for which it is not possible to use other isotopic measurement techniques, for example because of sample heterogeneity. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Label-Free, Real-Time Monitoring of Biomass Processing with Stimulated Raman Scattering Microscopy,

ANGEWANDTE CHEMIE, Issue 32 2010
Brian
,Chemische Videos" ohne Einfärben von Lignin und Cellulose in frischem pflanzlichem Gewebe wurden während eines Schritts der Prozessierung von Biomasse in Biokraftstoffe mithilfe von stimulierter Raman-Mikroskopie aufgenommen. Auf diese Weise lässt sich der Ligninabbau in der Zellwand mit Submikrometerauflösung sowie hoher Empfindlichkeit und zeitlicher Auflösung verfolgen. [source]

Release of (1,3)-,-D-Glucan from Depth-type Membrane Filters and Their In Vitro Effects on Proinflammatory Cytokine Production

ARTIFICIAL ORGANS, Issue 8 2003
Atsushi Ohata
Abstract:, To clarify the origin of (1,3)-,-D-glucan in blood products and assess the biological activity of filter extracts, we evaluated (1,3)-,-D-glucan extraction from depth filters used to process blood products and their in vitro effects on proinflammatory cytokine production from macrophages. Cellulose or nylon filters were analyzed for (1,3)-,-D-glucan using the Fungitec G test. To evaluate the biological activity of the filter extracts, Mono Mac 6 cells (a human macrophage cell line) were cultured with filter extracts with or without lipopolysaccharide, and tumor necrosis factor-alpha (TNF-,) and interleukin-1 beta (IL-1,) concentrations in the culture media were measured. (1,3)-,-D-Glucan was released from seven cellulose filters but the nylon filter level was undetectable. Proinflammatory cytokine production ranged from 74.3% to 119.0% of the control for TNF-, and 81.2% to 115.9% for IL-1,. TNF-, and IL-1, levels were low without lipopolysaccharide. The data indicate that (1,3)-,-D-glucan in blood products is contaminated with the depth filters and that these filter extracts modulate proinflammatory cytokine production from macrophages. [source]

Simultaneous Saccharification and Co-Fermentation of Crystalline Cellulose and Sugar Cane Bagasse Hemicellulose Hydrolysate to Lactate by a Thermotolerant Acidophilic Bacillus sp.

BIOTECHNOLOGY PROGRESS, Issue 5 2005
Milind A. Patel
Polylactides produced from renewable feedstocks, such as corn starch, are being developed as alternatives to plastics derived from petroleum. In addition to corn, other less expensive biomass resources can be readily converted to component sugars (glucose, xylose, etc.) by enzyme and/or chemical treatment for fermentation to optically pure lactic acid to reduce the cost of lactic acid. Lactic acid bacteria used by the industry lack the ability to ferment pentoses (hemicellulose-derived xylose and arabinose), and their growth and fermentation optima also differ from the optimal conditions for the activity of fungal cellulases required for depolymerization of cellulose. To reduce the overall cost of simultaneous saccharification and fermentation (SSF) of cellulose, we have isolated bacterial biocatalysts that can grow and ferment all sugars in the biomass at conditions that are also optimal for fungal cellulases. SSF of Solka Floc cellulose by one such isolate, Bacillus sp. strain 36D1, yielded l(+)-lactic acid at an optical purity higher than 95% with cellulase (Spezyme CE; Genencor International) added at about 10 FPU/g cellulose, with a product yield of about 90% of the expected maximum. Volumetric productivity of SSF to lactic acid was optimal between culture pH values of 4.5 and 5.5 at 50 °C. At a constant pH of 5.0, volumetric productivity of lactic acid was maximal at 55 °C. Strain 36D1 also co-fermented cellulose-derived glucose and sugar cane bagasse hemicellulose-derived xylose simultaneously (SSCF). In a batch SSCF of 40% acid-treated hemicellulose hydrolysate (over-limed) and 20 g/L Solka Floc cellulose, strain 36D1 produced about 35 g/L lactic acid in about 144 h with 15 FPU of Spezyme CE/g cellulose. The maximum volumetric productivity of lactic acid in this SSCF was 6.7 mmol/L (h). Cellulose-derived lactic acid contributed to about 30% of this total lactic acid. These results show that Bacillus sp. strain 36D1 is well-suited for simultaneous saccharification and co-fermentation of all of the biomass-derived sugars to lactic acid. [source]

Cellulose and Glass Fiber Affinity Membranes for the Chromatographic Separation of Biomolecules

BIOTECHNOLOGY PROGRESS, Issue 1 2004
Eli Ruckenstein
Macroporous cellulose and glass membranes were prepared from filter paper and glass fiber filter, respectively. To enhance their stability, the cellulose membranes were crosslinked with epichlorohydrin, and the glass membranes were crosslinked with glutaraldehyde or organic bifunctional silanes. Several pathways for the modification, activation, and ligand immobilization were used and compared. For cellulose membranes, the diazotization method provided the best results, whereas the glutaraldehyde method provided the best performance for glass membranes, regarding both their stability and ligand immobilization capacity. The characterization of the membranes was made by using a triazine dye, bovine serum albumin, and trypsin as test ligands. The membrane morphologies and the uniformities of ligand distribution across the membrane cartridges were investigated. Numerous affinity ligands were immobilized onto the membranes, and the prepared affinity membranes have been used to separate or purify concanavalin A, peroxidase, protease inhibitors, globulin, fibronectin, and other biomolecules. [source]

Subcritical Water Reaction Behavior of D -Glucose as a Model Compound for Biomass Using Two Different Continuous-Flow Reactor Configurations

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2009
T. Saito
Abstract Recently, cellulosic materials have been considered as a useful resource for the recovery of valuable chemicals and liquid fuels, etc. Cellulose is a homopolymer of D -glucose, which is often used as a model compound for biomass. Reactions of D -glucose in subcritical water as the reaction solvent were conducted using a single-flow-type reactor (S1) and an admixture-type reactor with feed and preheated-water flow (S2) at temperatures from 200 to 240,°C, pressures from 15 to 20 MPa, residence times from 40 to 120 s, and initial feed concentrations of 1.5,10 wt %. D -Glucose was converted into aldehydes, organic acids and furans, with mainly organic acids obtained at 240,°C. D -Glucose decomposition using reactors S1 and S2 revealed that the conversion rate of D -glucose was promoted more using S2 than by S1. The yield of furans with S1 was higher than with S2, while the yield of organic acids from S1 was lower than that from S2. [source]

The IBUS Process , Lignocellulosic Bioethanol Close to a Commercial Reality

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2008
J. Larsen
Abstract Integrated Biomass Utilization System (IBUS) is a new process for converting lignocellulosic waste biomass to bioethanol. Inbicon A/S has developed the IBUS process in a large-scale process development unit. This plant features new continuous and energy-efficient technology developed for pretreatment and liquefaction of lignocellulosic biomass and has now been operated and optimized for four years with promising results. In the IBUS process, biomass is converted using steam and enzymes only. The process is energy efficient due to very high dry matter content in all process steps and by integration with a power plant. Cellulose is converted to bioethanol and lignin to a high-quality solid biofuel which supply the process energy as well as a surplus of heat and power. Hemicellulose is used as feed molasses but in the future it could also be used for additional ethanol production or other valuable products. Feasibility studies of the IBUS process show that the production price for lignocellulosic bioethanol is close to the world market price for fuel ethanol. There is still room for optimization , and lignocellulosic bioethanol is most likely a commercial alternative to fossil transport fuels before 2012. [source]

Ermittlung des Verdichtungsverhaltens von kohäsiven kompressiblen Schüttgütern mit einer Hydraulikpresse

CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 6 2006
P. Müller
Abstract Die Verdichtung von kohäsiven Schüttgütern wird in der Industrie oft verwendet, um Agglomerate mit einer besseren Transport-, Dosier- und Fließfähigkeit herzustellen. Das Ergebnis des Agglomerationsprozesses wird wesentlich von den Eigenschaften des Aufgabegutes bestimmt. Eine Hydraulikpresse wurde für die Untersuchungen des Verdichtungsvorganges im Hochdruckbereich (p > 1 MPa) angewendet. In dieser Studie wird sowohl über die ermittelten Kompressionseigenschaften von Kalkstein, Bentonit und mikrokristalliner Cellulose als auch der mechanischen Eigenschaften der Agglomerate berichtet. Die Auswertung der ermittelten Druck-Dichte-Diagramme erfolgte mit einem neu entwickelten Zusammenhang. [source]

Selective Bifunctional Catalytic Conversion of Cellulose over Reshaped Ni Particles at the Tip of Carbon Nanofibers

CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 6 2010
Stijn Van, Vyver
Access to cellulose: Carbon nanofibers grown over Ni supported on ,-Al2O3 act as efficient catalysts for the one-pot conversion of cellulose to sugar alcohols, owing to the enhanced accessibility of the water-insoluble substrate towards the active catalytic sites. The new catalyst design concept yields unprecedented results for selective cellulose conversion using inexpensive Ni catalysts. [source]