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Sample records for strongly inhibited cellulose

  1. Strong cellulase inhibition by Mannan polysaccharides in cellulose conversion to sugars.

    Science.gov (United States)

    Kumar, Rajeev; Wyman, Charles E

    2014-07-01

    Cellulase enzymes contribute a major fraction of the total cost for biological conversion of lignocellulosic biomass to fuels and chemicals. Although a several fold reduction in cellulase production costs and enhancement of cellulase activity and stability have been reported in recent years, sugar yields are still lower at low enzyme doses than desired commercially. We recently reported that hemicellulose xylan and its oligomers strongly inhibit cellulase and that supplementation of cellulase with xylanase and β-xylosidase would significantly reduce such inhibition. In this study, mannan polysaccharides and their enzymatically prepared hydrolyzates were discovered to be strongly inhibitory to fungal cellulase in cellulose conversion (>50% drop in % relative conversion), even at a small concentration of 0.1 g/L, and inhibition was much greater than experienced by other known inhibitors such as cellobiose, xylooligomers, and furfural. Furthermore, cellulase inhibition dramatically increased with heteromannan loading and mannan substitution with galactose side units. In general, enzymatically prepared hydrolyzates were less inhibitory than their respective mannan polysaccharides except highly substituted ones. Supplementation of cellulase with commercial accessory enzymes such as xylanase, pectinase, and β-glucosidase was effective in greatly relieving inhibition but only for less substituted heteromannans. However, cellulase supplementation with purified heteromannan specific enzymes relieved inhibition by these more substituted heteromannans as well, suggesting that commercial preparations need to have higher amounts of such activities to realize high sugar yields at the low enzyme protein loadings needed for low cost fuels production. © 2014 Wiley Periodicals, Inc.

  2. Probing inhibitory effects of nanocrystalline cellulose: inhibition versus surface charge

    Science.gov (United States)

    Male, Keith B.; Leung, Alfred C. W.; Montes, Johnny; Kamen, Amine; Luong, John H. T.

    2012-02-01

    NCC derived from different biomass sources was probed for its plausible cytotoxicity by electric cell-substrate impedance sensing (ECIS). Two different cell lines, Spodoptera frugiperda Sf9 insect cells and Chinese hamster lung fibroblast V79, were exposed to NCC and their spreading and viability were monitored and quantified by ECIS. Based on the 50%-inhibition concentration (ECIS50), none of the NCC produced was judged to have any significant cytotoxicity on these two cell lines. However, NCC derived from flax exhibited the most pronounced inhibition on Sf9 compared to hemp and cellulose powder. NCCs from flax and hemp pre-treated with pectate lyase were also less inhibitory than NCCs prepared from untreated flax and hemp. Results also suggested a correlation between the inhibitory effect and the carboxylic acid contents on the NCC.

  3. Cellulose synthesis inhibition, cell expansion, and patterns of cell wall deposition in Nitella internodes

    International Nuclear Information System (INIS)

    Richmond, P.A.; Metraux, J.P.

    1984-01-01

    The authors have investigated the pattern of wall deposition and maturation and correlated it with cell expansion and cellulose biosynthesis. The herbicide 2,6-dichlorobenzonitrile (DCB) was found to be a potent inhibitor of cellulose synthesis, but not of cell expansion in Nitella internodal cells. Although cellulose synthesis is inhibited during DCB treatment, matrix substances continue to be synthesized and deposited. The inhibition of cellulose microfibril deposition can be demonstrated by various techniques. These results demonstrate that matrix deposition is by apposition, not by intussusception, and that the previously deposited wall moves progressively outward while stretching and thinning as a result of cell expansion

  4. Strong and Optically Transparent Films Prepared Using Cellulosic Solid Residue Recovered from Cellulose Nanocrystals Production Waste Stream

    Science.gov (United States)

    Qianqian Wang; J.Y. Zhu; John M. Considine

    2013-01-01

    We used a new cellulosic material, cellulosic solid residue (CSR), to produce cellulose nanofibrils (CNF) for potential high value applications. Cellulose nanofibrils (CNF) were produced from CSR recovered from the hydrolysates (waste stream) of acid hydrolysis of a bleached Eucalyptus kraft pulp (BEP) to produce nanocrystals (CNC). Acid hydrolysis greatly facilitated...

  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. Cellulose nanofiber isolation from palm oil Empty Fruit Bunches (EFB) through strong acid hydrolysis

    Science.gov (United States)

    Setyaningsih, Dwi; Uju; Muna, Neli; Isroi; Budi Suryawan, Nyoman; Azid Nurfauzi, Ami

    2018-03-01

    The palm oil industry produces about 25-26% of palm oil empty fruit bunches. The empty fruit bunch of palm oil contains cellulose up to 36.67%. This is a good opportunity for the synthesis of cellulose nanofiber (CNF). Cellulose nanofiber is a nano-sized cellulose material that has unique physical and mechanical properties. The synthesis was performed using a strong acid method with sulfuric acid. Sulfuric acid removes the amorphous region of cellulose so that the crystalline part can be isolated. CNF yield measurement showed that temperature, time, acid concentration, and interaction between each factor were affecting significantly to CNF yield. The result showed that yield of 14.98 grams, was obtained by hydrolysis at 35°C for 6 hours and 55% acid concentration. The crystallinity measurement showed that the temperature, time, acid concentration, and interaction between each factor during hydrolysis were not affected significantly to percent value of CNF crystallinity. The result showed that 31.1% of crystallinity, was obtained by hydrolysis at 45°C for 3 hours and 55% of acid concentration. The size measurement showed that the temperature, time, acid concentration and interaction between each factor were affected significantly. The result showed 894.25 nm as the best result, obtained by hydrolysis with 35°C and 60% acid concentration for 6 hours. CNF color was white with the best dispersion of hydrolysis at 35°C of 55% for 6 hours.

  7. The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

    Science.gov (United States)

    Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

    2013-04-01

    Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Validation of Inhibition Effect in the Cellulose Hydrolysis: a Dynamic Modelling Approach

    DEFF Research Database (Denmark)

    Morales Rodriguez, Ricardo; Tsai, Chien-Tai; Meyer, Anne S.

    2011-01-01

    Enzymatic hydrolysis is one of the main steps in the processing of bioethanol from lignocellulosic raw materials. However, complete understanding of the underlying phenomena is still under development. Hence, this study has focused on validation of the inhibition effects in the cellulosic biomass...... for parameter estimation (calibration) and validation purposes. The model predictions using calibrated parameters have shown good agreement with the validation data sets, which provides credibility to the model structure and the parameter values....

  9. Product inhibition of enzymatic hydrolysis of cellulose: are we running the reactions all wrong?

    DEFF Research Database (Denmark)

    Meyer, Anne S.

    2012-01-01

    cellobiose and glucose. The reported KI for glucose on the T. reesei cellulases and -glucosidase varies from 0.04 to 5 g/L. The type of inhibition is debated, and probably varies for different -glucosidases, but with a required goal of sufficient glucose concentration to support ethanol concentrations....... This is because the currently used Trichoderma reesei derived cellulases, i.e. exoglucanases (mainly the cellobiohydrolases Cel7A and Cel6A), endo-1,4--glucanases, and now boosted with -glucosidase and other enzymes, now considered the “industry standard” enzymes, are significantly inhibited by the products...... of minimum ∼5–6% v/v, the glucose product concentrations exceed the critical limit for product inhibition. Hence, regardless of the recent progress in enzyme development for cellulose hydrolysis, the glucose product inhibition remains an issue, which is exacerbated as the reaction progresses, especially...

  10. Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

    Science.gov (United States)

    2011-01-01

    Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX) and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy. PMID:21702938

  11. Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

    Directory of Open Access Journals (Sweden)

    Qing Qing

    2011-06-01

    Full Text Available Abstract Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy.

  12. Mitigation of Humic Acid Inhibition in Anaerobic Digestion of Cellulose by Addition of Various Salts

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    Samet Azman

    2015-03-01

    Full Text Available Humic compounds are inhibitory to the anaerobic hydrolysis of cellulosic biomass. In this study, the impact of salt addition to mitigate the inhibitory effects of humic compounds was investigated. The experiment was conducted using batch tests to monitor the anaerobic hydrolysis of cellulose in the presence of humic acid. Sodium, potassium, calcium, magnesium and iron salts were tested separately for their efficiency to mitigate humic acid inhibition. All experiments were done under mesophilic conditions (30 °C and at pH 7. Methane production was monitored online, using the Automatic Methane Potential Test System. Methane production, soluble chemical oxygen demand and volatile fatty acid content of the samples were measured to calculate the hydrolysis efficiencies. Addition of magnesium, calcium and iron salts clearly mitigated the inhibitory effects of humic acid and hydrolysis efficiencies reached up to 75%, 65% and 72%, respectively, which were similar to control experiments. Conversely, potassium and sodium salts addition did not mitigate the inhibition and hydrolysis efficiencies were found to be less than 40%. Mitigation of humic acid inhibition via salt addition was also validated by inductively coupled plasma atomic emission spectroscopy analyses, which showed the binding capacity of different cations to humic acid.

  13. Hierarchically porous, ultra-strong reduced graphene oxide-cellulose nanocrystal sponges for exceptional adsorption of water contaminants

    DEFF Research Database (Denmark)

    Yousefi, Nariman; Wong, Kerwin K.W.; Hosseinidoust, Zeinab

    2018-01-01

    Self-assembly of graphene oxide (GO) nanosheets into porous 3D sponges is a promising approach to exploit their capacity to adsorb contaminants while facilitating the recovery of the nanosheets from treated water. Yet, forming mechanically robust sponges with suitable adsorption properties presents...... a significant challenge. Ultra-strong and highly porous 3D sponges are formed using GO, vitamin C (VC), and cellulose nanocrystals (CNCs) - natural nanorods isolated from wood pulp. CNCs provide a robust scaffold for the partially reduced GO (rGO) nanosheets resulting in an exceptionally stiff nanohybrid....... The concentration of VC as a reducing agent plays a critical role in tailoring the pore architecture of the sponges. By using excess amounts of VC, a unique hierarchical pore structure is achieved, where VC grains act as soft templates for forming millimeter-sized pores, the walls of which are also porous...

  14. Achieving a Collapsible, Strong, and Highly Thermally Conductive Film Based on Oriented Functionalized Boron Nitride Nanosheets and Cellulose Nanofiber.

    Science.gov (United States)

    Wu, Kai; Fang, Jinchao; Ma, Jinrui; Huang, Rui; Chai, Songgang; Chen, Feng; Fu, Qiang

    2017-09-06

    Boron nitride nanosheet (BNNS) films receive wide attention in both academia and industry because of their high thermal conductivity (TC) and good electrical insulation capability. However, the brittleness and low strength of the BNNS film largely limit its application. Herein, functionalized BNNSs (f-BNNSs) with a well-maintained in-plane crystalline structure were first prepared utilizing urea in the aqueous solution via ball-milling for the purpose of improving their stability in water and enhancing the interaction with the polymer matrix. Then, a biodegradable and highly thermally conductive film with an orderly oriented structure based on cellulose nanofibers (CNFs) and f-BNNSs was prepared just by simple vacuum-assisted filtration. The modification of the BNNS and the introduction of the CNF result in a better orientation of the f-BNNS, sufficient connection between f-BNNS themselves, and strong interaction between f-BNNS and CNF, which not only make the prepared composite film strong and tough but also possess higher in-plane TC. An increase of 70% in-plane TC, 63.2% tensile strength, and 77.8% elongation could be achieved for CNF/f-BNNS films, compared with that for CNF/BNNS films at the filler content of 70%. Although at such a high f-BNNS content, this composite film can be bended and folded. It is even more interesting to find that the in-plane TC could be greatly enhanced with the decrease of the thickness of the film, and a value of 30.25 W/m K can be achieved at the thickness of ∼30 μm for the film containing 70 wt % f-BNNS. We believe that this highly thermally conductive film with good strength and toughness could have potential applications in next-generation highly powerful and collapsible electronic devices.

  15. Synchronisation hubs in the visual cortex may arise from strong rhythmic inhibition during gamma oscillations.

    Science.gov (United States)

    Folias, Stefanos E; Yu, Shan; Snyder, Abigail; Nikolić, Danko; Rubin, Jonathan E

    2013-09-01

    Neurons in the visual cortex exhibit heterogeneity in feature selectivity and the tendency to generate action potentials synchronously with other nearby neurons. By examining visual responses from cat area 17 we found that, during gamma oscillations, there was a positive correlation between each unit's sharpness of orientation tuning, strength of oscillations, and propensity towards synchronisation with other units. Using a computational model, we demonstrated that heterogeneity in the strength of rhythmic inhibitory inputs can account for the correlations between these three properties. Neurons subject to strong inhibition tend to oscillate strongly in response to both optimal and suboptimal stimuli and synchronise promiscuously with other neurons, even if they have different orientation preferences. Moreover, these strongly inhibited neurons can exhibit sharp orientation selectivity provided that the inhibition they receive is broadly tuned relative to their excitatory inputs. These results predict that the strength and orientation tuning of synaptic inhibition are heterogeneous across area 17 neurons, which could have important implications for these neurons' sensory processing capabilities. Furthermore, although our experimental recordings were conducted in the visual cortex, our model and simulation results can apply more generally to any brain region with analogous neuron types in which heterogeneity in the strength of rhythmic inhibition can arise during gamma oscillations. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Thienoquinolins exert diuresis by strongly inhibiting UT-A urea transporters

    Science.gov (United States)

    Ren, Huiwen; Wang, Yanhua; Xing, Yongning; Ran, Jianhua; Liu, Ming; Lei, Tianluo; Zhou, Hong; Li, Runtao; Sands, Jeff M.

    2014-01-01

    Urea transporters (UT) play an important role in the urine concentration mechanism by mediating intrarenal urea recycling, suggesting that UT inhibitors could have therapeutic use as a novel class of diuretic. Recently, we found a thienoquinolin UT inhibitor, PU-14, that exhibited diuretic activity. The purpose of this study was to identify more potent UT inhibitors that strongly inhibit UT-A isoforms in the inner medullary collecting duct (IMCD). Efficient thienoquinolin UT inhibitors were identified by structure-activity relationship analysis. Urea transport inhibition activity was assayed in perfused rat terminal IMCDs. Diuretic activity of the compound was determined in rats and mice using metabolic cages. The results show that the compound PU-48 exhibited potent UT-A inhibition activity. The inhibition was 69.5% with an IC50 of 0.32 μM. PU-48 significantly inhibited urea transport in perfused rat terminal IMCDs. PU-48 caused significant diuresis in UT-B null mice, which indicates that UT-A is the target of PU-48. The diuresis caused by PU-48 did not change blood Na+, K+, or Cl− levels or nonurea solute excretion in rats and mice. No toxicity was detected in cells or animals treated with PU-48. The results indicate that thienoquinolin UT inhibitors induce a diuresis by inhibiting UT-A in the IMCD. This suggests that they may have the potential to be developed as a novel class of diuretics with fewer side effects than classical diuretics. PMID:25298523

  17. Mechanism of product inhibition for cellobiohydrolase Cel7A during hydrolysis of insoluble cellulose

    DEFF Research Database (Denmark)

    Olsen, Johan P.; Alasepp, Kadri; Kari, Jeppe

    2016-01-01

    The cellobiohydrolase cellulase Cel7A is extensively utilized in industrial treatment of lignocellulosic biomass under conditions of high product concentrations, and better understanding of inhibition mechanisms appears central in attempts to improve the efficiency of this process. We have...... the lines of conventional enzyme kinetic theory. We found that the product cellobiose lowered the maximal rate without affecting the Michaelis constant, and this kinetic pattern could be rationalized by two fundamentally distinct molecular mechanisms. One was simple reversibility, that is, an increasing...

  18. Inhibition and kinetic studies of cellulose- and hemicellulose-degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

    Science.gov (United States)

    Surendran, A; Siddiqui, Y; Ali, N S; Manickam, S

    2018-06-01

    Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study. Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (V max and K m ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature. These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma. The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds. © 2018 The Society for Applied Microbiology.

  19. Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

    Science.gov (United States)

    Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

    2012-01-01

    This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

  20. PERIPUBERTAL PROCHLORAZ EXPOSURE STRONGLY INHIBITS TESTOSTERONE PRODUCTION, BUT HAS WEAK EFFECTS ON PUBERTY

    Science.gov (United States)

    Prochloraz (PCZ) is an imidazole fungicide that inhibits steroidogenesis and acts as an androgen receptor antagonist. We hypothesized that pubertal exposure to prochloraz would delay preputial separation and development of reproductive organs. Sprague Dawley rats were dosed wit...

  1. STRUCTURAL ASPECTS OF STRONG INHIBITION AND ROLE OF SCAFFOLD FOR SERINE PROTEASE INHIBITORS

    Directory of Open Access Journals (Sweden)

    Jhimli Dasgupta

    2011-12-01

    Full Text Available Canonical serine protease inhibitors inhibit their cognate enzymes by binding tightly at the enzyme active site in a substrate-like manner, being cleaved extremely slowly compared to a true substrate. They interact with cognate enzymes through P3-P2 region of the inhibitory loop while the scaffold hardly makes any contact. Neighbouring scaffolding residues like arginine or asparagine shape-up the inhibitory loop and religate the cleaved scissile bond. The specificity of the inhibitor can be altered by mutating the hyper solvent accessible P1 residue without changing loop-scaffold interactions. To understand the loop-scaffold compatibility, we prepared three chimeric proteins ECIL-WCIS , ETIL-WCIS , and STIL-WCIS , where the inhibitory loops of ECI, ETI, and STI were placed on the scaffold of their homologue WCI. Results showed that although ECIL-WCIS and STIL-WCIS behave like inhibitors, ETIL-WCIS behaves like a substrate. Crystal structure of ETIL-WCIS and its comparison with ETI indicated that three novel scaffolding residues Trp88, Arg74, and Tyr113 in ETI act as barrier to confine the inhibitory loop to canonical conformation. Absence of this barrier in the scaffold of WCI makes the inhibitory loop flexible in ETIL-WCIS leading to a loss of canonical conformation, explaining its substrate-like behaviour. Furthermore, complex structures of the inhibitors with their cognate enzymes indicate that rigidification of the inhibitory loop at the enzyme active site is necessary for efficient inhibition.

  2. Rare sugar D-allose strongly induces thioredoxin-interacting protein and inhibits osteoclast differentiation in Raw264 cells.

    Science.gov (United States)

    Yamada, Kana; Noguchi, Chisato; Kamitori, Kazuyo; Dong, Youyi; Hirata, Yuko; Hossain, Mohammad A; Tsukamoto, Ikuko; Tokuda, Masaaki; Yamaguchi, Fuminori

    2012-02-01

    Oxidative stress modulates the osteoclast differentiation via redox systems, and thioredoxin 1 (Trx) promotes the osteoclast formation by regulating the activity of transcription factors. The function of Trx is known to be regulated by its binding partner, thioredoxin-interacting protein (TXNIP). We previously reported that the expression of TXNIP gene is strongly induced by a rare sugar D-allose. In this study, we tested the hypothesis that D-allose could inhibit the osteoclast differentiation by regulating the Trx function. We used a murine Raw264 cell line that differentiates to the osteoclast by the receptor activator of nuclear factor-κB ligand (RANKL) treatment. The effect of sugars was evaluated by tartrate-resistant acid phosphatase staining. The expression and localization of TXNIP and Trx protein were examined by Western blotting and immunohistochemisty. The activity of the nuclear factor-κB, nuclear factor of activated T cells, and activator protein 1 transcription factors was measured by the luciferase reporter assay. The addition of D-allose (25 mmol/L) inhibited the osteoclast differentiation down to 9.53% ± 1.27% of a receptor activator of nuclear factor-κB ligand-only treatment. During the osteoclast differentiation, a significant increase of TNXIP was observed by D-allose treatment. The immunohistochemical analysis showed that both Trx and TXNIP existed in the nucleus in preosteoclasts and osteoclasts. Overexpression of TXNIP by plasmid transfection also inhibited the osteoclast formation, indicating the functional importance of TXNIP for the osteoclast differentiation. Transcriptional activity of the activator protein 1, nuclear factor-κB, and nuclear factor of activated T cells, known to be modulated by Trx, were inhibited by D-allose. In conclusion, our data indicate that D-allose is a strong inhibitor of the osteoclast differentiation, and this effect could be caused by TXNIP induction and a resulting inhibition of the Trx function

  3. Estradiol and Progesterone Strongly Inhibit the Innate Immune Response of Mononuclear Cells in Newborns ▿

    Science.gov (United States)

    Giannoni, Eric; Guignard, Laurence; Knaup Reymond, Marlies; Perreau, Matthieu; Roth-Kleiner, Matthias; Calandra, Thierry; Roger, Thierry

    2011-01-01

    Newborns are particularly susceptible to bacterial infections due to qualitative and quantitative deficiencies of the neonatal innate immune system. However, the mechanisms underlying these deficiencies are poorly understood. Given that fetuses are exposed to high concentrations of estradiol and progesterone during gestation and at time of delivery, we analyzed the effects of these hormones on the response of neonatal innate immune cells to endotoxin, bacterial lipopeptide, and Escherichia coli and group B Streptococcus, the two most common causes of early-onset neonatal sepsis. Here we show that at concentrations present in umbilical cord blood, estradiol and progesterone are as powerful as hydrocortisone for inhibition of cytokine production by cord blood mononuclear cells (CBMCs) and newborn monocytes. Interestingly, CBMCs and newborn monocytes are more sensitive to the effects of estradiol and progesterone than adult peripheral blood mononuclear cells and monocytes. This increased sensitivity is associated with higher expression levels of estrogen and membrane progesterone receptors but is independent of a downregulation of Toll-like receptor 2 (TLR2), TLR4, and myeloid differentiation primary response gene 88 in newborn cells. Estradiol and progesterone mediate their anti-inflammatory activity through inhibition of the NF-κB pathway but not the mitogen-activated protein kinase pathway in CBMCs. Altogether, these results suggest that elevated umbilical cord blood concentrations of estradiol and progesterone acting on mononuclear cells expressing high levels of steroid receptors contribute to impair innate immune responses in newborns. Therefore, intrauterine exposure to estradiol and progesterone may participate in increasing susceptibility to infection during the neonatal period. PMID:21518785

  4. Kaempferol nanoparticles achieve strong and selective inhibition of ovarian cancer cell viability

    Science.gov (United States)

    Luo, Haitao; Jiang, Bingbing; Li, Bingyun; Li, Zhaoliang; Jiang, Bing-Hua; Chen, Yi Charlie

    2012-01-01

    Ovarian cancer is one of the leading causes of cancer death for women throughout the Western world. Kaempferol, a natural flavonoid, has shown promise in the chemoprevention of ovarian cancer. A common concern about using dietary supplements for chemoprevention is their bioavailability. Nanoparticles have shown promise in increasing the bioavailability of some chemicals. Here we developed five different types of nanoparticles incorporating kaempferol and tested their efficacy in the inhibition of viability of cancerous and normal ovarian cells. We found that positively charged nanoparticle formulations did not lead to a significant reduction in cancer cell viability, whereas nonionic polymeric nanoparticles resulted in enhanced reduction of cancer cell viability. Among the nonionic polymeric nanoparticles, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) nanoparticles incorporating kaempferol led to significant reduction in cell viability of both cancerous and normal cells. Poly(DL-lactic acid-co-glycolic acid) (PLGA) nanoparticles incorporating kaempferol resulted in enhanced reduction of cancer cell viability together with no significant reduction in cell viability of normal cells compared with kaempferol alone. Therefore, both PEO-PPO-PEO and PLGA nanoparticle formulations were effective in reducing cancer cell viability, while PLGA nanoparticles incorporating kaempferol had selective toxicity against cancer cells and normal cells. A PLGA nanoparticle formulation could be advantageous in the prevention and treatment of ovarian cancers. On the other hand, PEO-PPO-PEO nanoparticles incorporating kaempferol were more effective inhibitors of cancer cells, but they also significantly reduced the viability of normal cells. PEO-PPO-PEO nanoparticles incorporating kaempferol may be suitable as a cancer-targeting strategy, which could limit the effects of the nanoparticles on normal cells while retaining their potency against cancer cells. We

  5. Biodegradation behaviors of cellulose nanocrystals -PVA nanocomposites

    Directory of Open Access Journals (Sweden)

    Mahdi Rohani

    2014-11-01

    Full Text Available In this research, biodegradation behaviors of cellulose nanocrystals-poly vinyl alcohol nanocomposites were investigated. Nanocomposite films with different filler loading levels (3, 6, 9 and 12% by wt were developed by solvent casting method. The effect of cellulose nanocrystals on the biodegradation behaviors of nanocomposite films was studied. Water absorption and water solubility tests were performed by immersing specimens into distilled water. The characteristic parameter of diffusion coefficient and maximum moisture content were determined from the obtained water absorption curves. The water absorption behavior of the nanocomposites was found to follow a Fickian behavior. The maximum water absorption and diffusion coefficients were decreased by increasing the cellulose nanocrystals contents, however the water solubility decrease. The biodegradability of the films was investigated by immersing specimens into cellulase enzymatic solution as well as by burial in soil. The results showed that adding cellulose nanocrystals increase the weight loss of specimens in enzymatic solution but decrease it in soil media. The limited biodegradability of specimens in soil media attributed to development of strong interactions with solid substrates that inhibit the accessibility of functional groups. Specimens with the low degree of hydrolysis underwent extensive biodegradation in both enzymatic and soil media, whilst specimens with the high degree of hydrolysis showed recalcitrance to biodegradation under those conditions.

  6. A Novel Variant of Narrow-Spectrum Antifungal Bacterial Lipopeptides That Strongly Inhibit Ganoderma boninense.

    Science.gov (United States)

    Pramudito, Theodorus Eko; Agustina, Delia; Nguyen, Thi Kim Ngan; Suwanto, Antonius

    2018-03-01

    Bacterial antifungal cyclic lipopeptides (ACLs) have become a promising alternative to synthetic fungicide to control pathogenic fungi. Bacillus sp. is known to produce three families of ACL, namely iturin, surfactin, and fengycin. In this paper, we characterized the ACLs produced by B. methylotrophicus HC51 (referred as HC51) mainly regarding its composition and effectivity against fungal plant pathogen. HC51 culture was tested against various pathogenic fungi and the ACLs were extracted and analyzed using liquid chromatography-electrospray ionization mass spectrometry. HC51 showed strong antifungal activity against the plant pathogens Ganoderma sp. and Fusarium sp. Cell-free methanol extract of HC51 contains iturin A and various variants of fengycin. C16 fengycin A was present in four fractions which indicates it as a major component of ACL from HC51. Five variants of fengycin were detected, four of which had been previously reported. We found a novel C17 fengycin F that is characterized by a substitution of L-ornithine into lysine. Considering that L-ornithine is an important building block of fengycin, this substitution suggests the possibility of an alternative pathway for fengycin biosynthesis.

  7. Platelet-Derived Growth Factor-Receptor α Strongly Inhibits Melanoma Growth In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Debora Faraone

    2009-08-01

    Full Text Available Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Rα may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Rα respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Rα. Proliferation was rescued by PDGF-Rα inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Rα mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Rα was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Rα show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Bα and a marked increase of p38γ, mitogen-activated protein kinase kinase 3, and signal regulatory protein α1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Rα reached a significant 70% inhibition of primary melanoma growth (P < .001 and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Rα strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

  8. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    Directory of Open Access Journals (Sweden)

    Andong eGong

    2015-10-01

    Full Text Available Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these pests is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production in the field and during storage.

  9. A Dynamic Model for Cellulosic Biomass Hydrolysis: a Comprehensive Analysis and Validation of Hydrolysis and Product Inhibition Mechanisms

    DEFF Research Database (Denmark)

    Tsai, Chien Tai; Morales Rodriguez, Ricardo; Sin, Gürkan

    2014-01-01

    product inhibitors such as glucose, cellobiose and xylose) to test the hydrolysis and product inhibition mechanisms of the model. A nonlinear least squares method was used to identify the model and estimate kinetic parameters based on the experimental data. The suitable mathematical model for industrial...... application was selected among the proposed models based on statistical information (weighted sum of square errors). The analysis showed that transglycosylation plays a key role at high glucose levels. It also showed that the values of parameters depend on the selected experimental data used for parameter....... As long as these type of models are used within the boundary of their validity (substrate type, enzyme source and substrate concentration), they can support process design and technology improvement efforts at pilot and full-scale studies....

  10. Cellulose is not just cellulose

    DEFF Research Database (Denmark)

    Hidayat, Budi Juliman; Felby, Claus; Johansen, Katja Salomon

    2012-01-01

    are not regions where free cellulose ends are more abundant than in the bulk cell wall. In more severe cases cracks between fibrils form at dislocations and it is possible that the increased accessibility that these cracks give is the reason why hydrolysis of cellulose starts at these locations. If acid...... or enzymatic hydrolysis of plant cell walls is carried out simultaneously with the application of shear stress, plant cells such as fibers or tracheids break at their dislocations. At present it is not known whether specific carbohydrate binding modules (CBMs) and/or cellulases preferentially access cellulose...

  11. Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass.

    Science.gov (United States)

    Li, Yun; Qi, Benkun; Wan, Yinhua

    2014-09-01

    Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30 g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Potential of carboxymethyl cellulose coating and low dose gamma irradiation to maintain storage quality, inhibit fungal growth and extend shelf-life of cherry fruit.

    Science.gov (United States)

    Hussain, P R; Rather, S A; Suradkar, P; Parveen, S; Mir, M A; Shafi, F

    2016-07-01

    Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation was tested for maintaining the storage quality, inhibiting fungal incidence and extending shelf-life of cherry fruit. Two commercial cherry varieties viz. Misri and Double after harvest at commercial maturity were coated with CMC at levels 0.5-1.0 % w/v and gamma irradiated at 1.2 kGy. The treated fruit including control was stored under ambient (temperature 25 ± 2 °C, RH 70 %) and refrigerated (temperature 3 ± 1 °C, RH 80 %) conditions for evaluation of various physico-chemical parameters. Fruits were evaluated after every 3 and 7 days under ambient and refrigerated conditions. CMC coating alone at levels 0.5 and 0.75 % w/v was not found effective with respect to mold growth inhibition under either of the two conditions. Individual treatment of CMC coating at 1.0 % w/v and 1.2 kGy irradiation proved helpful in delaying the onset of mold growth up to 5 and 8 days of ambient storage. During post-refrigerated storage at 25 ± 2 °C, RH 70 %, irradiation alone at 1.2 kGy gave further 4 days extension in shelf-life of cherry varieties following 28 days of refrigeration. All combinatory treatments of CMC coating and irradiation proved beneficial in maintaining the storage quality as well as delaying the decaying of cherry fruit during post-refrigerated storage at 25 ± 2 °C, RH 70 % but, combination of CMC at 1.0 % w/v and 1.2 kGy irradiation was found significantly ( p  ≤ 0.05) superior to all other treatments in maintaining the storage quality and delaying the decaying of cherry fruit. The above combinatory treatment besides maintaining storage quality resulted in extension of 6 days in shelf life of cherry varieties during post-refrigerated storage at 25 ± 2 °C, RH 80 % following 28 days of refrigeration. Above Combination treatment gave a maximum of 2.3 and 1.5 log reduction in yeast and mold count of cherry fruits after 9 and 28

  13. Cellulose-Hemicellulose Interactions at Elevated Temperatures Increase Cellulose Recalcitrance to Biological Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Himmel, Michael E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kumar, Rajeev [University of California, Riverside; Oak Ridge National Laboratory; ; Smith, Micholas Dean [Oak Ridge National Laboratory; University of Tennessee; Petridis, Loukas [Oak Ridge National Laboratory; University of Tennessee; Ong, Rebecca G. [Michigan Technological University; Cai, Charles M. [University of California, Riverside; Oak Ridge National Laboratory; Balan, Venkatesh [University of Houston; Dale, Bruce E. [Michigan State University; Ragauskas, Arthur J. [Oak Ridge National Laboratory; University of Tennessee; Smith, Jeremy C. [Oak Ridge National Laboratory; University of Tennessee; Wyman, Charles E. [University of California, Riverside; Oak Ridge National Laboratory

    2018-01-23

    It has been previously shown that cellulose-lignin droplets' strong interactions, resulting from lignin coalescence and redisposition on cellulose surface during thermochemical pretreatments, increase cellulose recalcitrance to biological conversion, especially at commercially viable low enzyme loadings. However, information on the impact of cellulose-hemicellulose interactions on cellulose recalcitrance following relevant pretreatment conditions are scarce. Here, to investigate the effects of plausible hemicellulose precipitation and re-association with cellulose on cellulose conversion, different pretreatments were applied to pure Avicel(R) PH101 cellulose alone and Avicel mixed with model hemicellulose compounds followed by enzymatic hydrolysis of resulting solids at both low and high enzyme loadings. Solids produced by pretreatment of Avicel mixed with hemicelluloses (AMH) were found to contain about 2 to 14.6% of exogenous, precipitated hemicelluloses and showed a remarkably much lower digestibility (up to 60%) than their respective controls. However, the exogenous hemicellulosic residues that associated with Avicel following high temperature pretreatments resulted in greater losses in cellulose conversion than those formed at low temperatures, suggesting that temperature plays a strong role in the strength of cellulose-hemicellulose association. Molecular dynamics simulations of hemicellulosic xylan and cellulose were found to further support this temperature effect as the xylan-cellulose interactions were found to substantially increase at elevated temperatures. Furthermore, exogenous, precipitated hemicelluloses in pretreated AMH solids resulted in a larger drop in cellulose conversion than the delignified lignocellulosic biomass containing comparably much higher natural hemicellulose amounts. Increased cellulase loadings or supplementation of cellulase with xylanases enhanced cellulose conversion for most pretreated AMH solids; however, this approach

  14. Opportunity for profitable investments in cellulosic biofuels

    International Nuclear Information System (INIS)

    Babcock, Bruce A.; Marette, Stephan; Treguer, David

    2011-01-01

    Research efforts to allow large-scale conversion of cellulose into biofuels are being undertaken in the US and EU. These efforts are designed to increase logistic and conversion efficiencies, enhancing the economic competitiveness of cellulosic biofuels. However, not enough attention has been paid to the future market conditions for cellulosic biofuels, which will determine whether the necessary private investment will be available to allow a cellulosic biofuels industry to emerge. We examine the future market for cellulosic biofuels, differentiating between cellulosic ethanol and 'drop-in' cellulosic biofuels that can be transported with petroleum fuels and have equivalent energy values. We show that emergence of a cellulosic ethanol industry is unlikely without costly government subsidies, in part because of strong competition from conventional ethanol and limits on ethanol blending. If production costs of drop-in cellulosic biofuels fall enough to become competitive, then their expansion will not necessarily cause feedstock prices to rise. As long as local supplies of feedstocks that have no or low-valued alternative uses exist, then expansion will not cause prices to rise significantly. If cellulosic feedstocks come from dedicated biomass crops, then the supply curves will have a steeper slope because of competition for land. (author)

  15. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  16. Cellulose Perversions

    Directory of Open Access Journals (Sweden)

    Maria H. Godinho

    2013-03-01

    Full Text Available Cellulose micro/nano-fibers can be produced by electrospinning from liquid crystalline solutions. Scanning electron microscopy (SEM, as well as atomic force microscopy (AFM and polarizing optical microscopy (POM measurements showed that cellulose-based electrospun fibers can curl and twist, due to the presence of an off-core line defect disclination, which was present when the fibers were prepared. This permits the mimicking of the shapes found in many systems in the living world, e.g., the tendrils of climbing plants, three to four orders of magnitude larger. In this work, we address the mechanism that is behind the spirals’ and helices’ appearance by recording the trajectories of the fibers toward diverse electrospinning targets. The intrinsic curvature of the system occurs via asymmetric contraction of an internal disclination line, which generates different shrinkages of the material along the fiber. The completely different instabilities observed for isotropic and anisotropic electrospun solutions at the exit of the needle seem to corroborate the hypothesis that the intrinsic curvature of the material is acquired during liquid crystalline sample processing inside the needle. The existence of perversions, which joins left and right helices, is also investigated by using suspended, as well as flat, targets. Possible routes of application inspired from the living world are addressed.

  17. Chapter 2.1 Integrated Production of Cellulose Nanofibrils and Cellulosic Biofuel by Enzymatic Hydrolysis of wood Fibers

    Science.gov (United States)

    Ronald Sabo; J.Y. Zhu

    2013-01-01

    One key barrier to converting woody biomass to biofuel through the sugar platform is the low efficiency of enzymatic cellulose saccharification due to the strong recalcitrance of the crystalline cellulose. Significant past research efforts in cellulosic biofuels have focused on overcoming the recalcitrance of lignocelluloses to enhance the saccharification of...

  18. Paper actuators made with cellulose and hybrid materials.

    Science.gov (United States)

    Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

    2010-01-01

    Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPap is quite comparable with other piezoelectric polymers. But, it is biodegradable, biocompatible, mechanically strong and thermally stable. To enhance ion migration effect in the cellulose, polypyrrole conducting polymer and ionic liquids were nanocoated on the cellulose film. This hybrid cellulose EAPap nanocomposite exhibits durable bending actuation in an ambient humidity and temperature condition. Fabrication, characteristics and performance of the cellulose EAPap and its hybrid EAPap materials are illustrated. Also, its possibility for remotely microwave-driven paper actuator is demonstrated.

  19. Modelling the bioconversion of cellulose into microbial products: rate limitations

    Energy Technology Data Exchange (ETDEWEB)

    Asenjo, J A

    1984-12-01

    The direct bioconversion of cellulose into microbial products carried out as a simultaneous saccharification and fermentation has a strong effect on the rates of cellulose degradation because cellobiose and glucose inhibition of the reaction are circumvented. A general mathematical model of the kinetics of this bioconversion has been developed. Its use in representing aerobic systems and in the analysis of the kinetic limitations has been investigated. Simulations have been carried out to find the rate limiting steps in slow fermentations and in rapid ones as determined by the specific rate of product formation. The requirements for solubilising and depolymerising enzyme activities (cellulase and cellobiase) in these systems has been determined. The activity that have been obtained for fungal cellulases are adequate for the kinetic requirements of the fastest fermentative strains. The results also show that for simultaneous bioconversions where strong cellobiose and glucose inhibition is overcome, no additional cellobiase is necessary to increase the rate of product formation. These results are useful for the selection of cellolytic micro-organisms and in the determination of enzymes to be cloned in recombinant strains. 17 references.

  20. Cellulose utilization: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Bassham, J A

    1975-01-01

    To summarize, the conversion of cellulose to ethanol via hydrolysis to glucose followed by fermentation appears to be highly efficient in terms of energy conservation, yield, and quality of product, especially when reasonably high quality cellulosic waste is available.

  1. 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.

  2. Characterization of cellulose nanowhiskers

    International Nuclear Information System (INIS)

    Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia

    2015-01-01

    Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

  3. Electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  4. Structural Identification of Lentinus edodes Cellulose Derivative that ...

    African Journals Online (AJOL)

    edodes cellulose in water surroundings that can efficiently inhibit aflatoxin production by Aspergillus flavus. .... blowing instrument, dissolved in methanol, and ... with NaBH4, neutralized with 50 % acetic acid, ... saccharides and peptides.

  5. Production and Properties of Carbon Nanotube/Cellulose Composite Paper

    OpenAIRE

    Maria, Kazi Hanium; Mieno, Tetsu

    2017-01-01

    Multiwalled carbon nanotube/cellulose composite papers have been prepared by mixing the cellulose with MWNT/gelatin solution and drying at room temperature. The CNTs form an interconnected network on the cellulose paper and as a result CNT paper sheet exhibits enhanced electrical properties and thermal stabilities. It is found that both sides of CNT paper sheet have the uniform electrical conductivities. The sheet exhibits strong microwave absorption in the microwave range of 10.5 GHz. The CN...

  6. Synthesis and characterization of amorphous cellulose from triacetate of cellulose

    International Nuclear Information System (INIS)

    Vega-Baudrit, Jose; Sibaja, Maria; Nikolaeva, Svetlana; Rivera A, Andrea

    2014-01-01

    It was carried-out a study for the synthesis and characterization of amorphous cellulose starting from cellulose triacetate. X-rays diffraction was used in order to obtain the cellulose crystallinity degree, also infrared spectroscopy FTIR was used. (author)

  7. CELLULOSIC NANOCOMPOSITES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2008-08-01

    Full Text Available Because of their wide abundance, their renewable and environmentally benign nature, and their outstanding mechanical properties, a great deal of attention has been paid recently to cellulosic nanofibrillar structures as components in nanocomposites. A first major challenge has been to find efficient ways to liberate cellulosic fibrils from different source materials, including wood, agricultural residues, or bacterial cellulose. A second major challenge has involved the lack of compatibility of cellulosic surfaces with a variety of plastic materials. The water-swellable nature of cellulose, especially in its non-crystalline regions, also can be a concern in various composite materials. This review of recent work shows that considerable progress has been achieved in addressing these issues and that there is potential to use cellulosic nano-components in a wide range of high-tech applications.

  8. Internally plasticised cellulose polymers

    International Nuclear Information System (INIS)

    Burnup, M.; Hayes, G.F.; Fydelor, P.J.

    1981-01-01

    Plasticised cellulose polymers comprise base polymer having a chain of β-anhydroglucose units joined by ether linkages, with at least one of said units carrying at least one chemically unreactive side chain derived from an allylic monomer or a vinyl substituted derivative of ferrocene. The side chains are normally formed by radiation grafting. These internally plasticised celluloses are useful in particular as inhibitor coatings for rocket motor propellants and in general wherever cellulose polymers are employed. (author)

  9. Glycerine Treated Nanofibrillated Cellulose Composites

    Directory of Open Access Journals (Sweden)

    Esra Erbas Kiziltas

    2016-01-01

    Full Text Available Glycerine treated nanofibrillated cellulose (GNFC was prepared by mixing aqueous nanofibrillated cellulose (NFC suspensions with glycerine. Styrene maleic anhydride (SMA copolymer composites with different loadings of GNFC were prepared by melt compounding followed by injection molding. The incorporation of GNFC increased tensile and flexural modulus of elasticity of the composites. Thermogravimetric analysis showed that as GNFC loading increased, the thermal stability of the composites decreased marginally. The incorporation of GNFC into the SMA copolymer matrix resulted in higher elastic modulus (G′ and shear viscosities than the neat SMA copolymer, especially at low frequencies. The orientation of rigid GNFC particles in the composites induced a strong shear thinning behavior with an increase in GNFC loading. The decrease in the slope of elastic modulus with increasing GNFC loading suggested that the microstructural changes of the polymer matrix can be attributed to the incorporation of GNFC. Scanning electron microscopy (SEM images of fracture surfaces show areas of GNFC agglomerates in the SMA matrix.

  10. Herbicide effect on 14C cellulose and 14C straw decomposition in soils. Influence of phenylcarbamates on biological activity

    International Nuclear Information System (INIS)

    Ramanujam, T.; Bellinck, Celine; Mayaudon, J.

    1979-01-01

    Aniline, 2,4-D, 2,4,5-T, simazine and paraquat have no effect on cellulose decomposition in soils. The monophenylcarbamates SN 38210, IPC and CIPC, applied at 500 ppm exert per contra an important inhibitory effect. The decomposition of straw is little influenced by the phenylcarbamates, 100 ppm of 2,4-D, 2,4,5-T or simazine significantly increase the decomposition of straw in a sandy soil. The diphenylcarbamate SN 38584 has little effect on biological activity of soils; this is strongly inhibited by application of 500 ppm of SN 38210. This inhibition may be reduced by amending the soil with lignin but addition of straw or cellulose doesn't enhance biological activity of soil. Addition of 5000 ppm of soil extract or humic acids reduces somewhat the toxicity of SN 38210 [fr

  11. Cellulose binding domain proteins

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc; Doi, Roy

    1998-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  12. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  13. Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

    Science.gov (United States)

    Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

    2016-01-01

    Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

  14. Cellulose: To depolymerize… or not to?

    Science.gov (United States)

    Coseri, Sergiu

    Oxidation of the primary OH groups in cellulose is a pivotal reaction both at lab and industrial scale, leading to the value-added products, i.e. oxidized cellulose which have tremendous applications in medicine, pharmacy and hi-tech industry. Moreover, the introduction of carboxyl moieties creates prerequisites for further cellulose functionalization through covalent attachment or electrostatic interactions, being an essential achievement designed to boost the area of cellulose-based nanomaterials fabrication. Various methods for the cellulose oxidation have been developed in the course of time, aiming the selective conversion of the OH groups. These methods use: nitrogen dioxide in chloroform, alkali metal nitrites and nitrates, strong acids alone or in combination with permanganates or sodium nitrite, ozone, and sodium periodate or lead (IV) tetraacetate. In the case of the last two reagents, cellulose dialdehydes derivatives are formed, which are further oxidized by sodium chlorite or hydrogen peroxide to form dicarboxyl groups. A major improvement in the cellulose oxidation was represented by the introduction of the stable nitroxyl radicals, such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). However, a major impediment for the researchers working in this area is related with the severe depolymerisation occurred during the TEMPO-mediated conversion of CH 2 OH into COOH groups. On the other hand, the cellulose depolymerisation represent the key step, in the general effort of searching for alternative strategies to develop new renewable, carbon-neutral energy sources. In this connection, exploiting the biomass feed stocks to produce biofuel and other low molecular organic compounds, involves a high amount of research to improve the overall reaction conditions, limit the energy consumption, and to use benign reagents. This work is therefore focused on the parallelism between these two apparently antagonist processes involving cellulose, building a necessary

  15. Fulton Cellulosic Ethanol Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Sumait, Necy [BlueFire Ethanol, Irvine, CA (United States); Cuzens, John [BlueFire Ethanol, Irvine, CA (United States); Klann, Richard [BlueFire Ethanol, Irvine, CA (United States)

    2015-07-24

    Final report on work performed by BlueFire on the deployment of acid hydrolysis technology to convert cellulosic waste materials into renewable fuels, power and chemicals in a production facility to be located in Fulton, Mississippi.

  16. Regiocontroll synthesis cellulose-graft-polycaprolactone copolymer (2,3-di-O-PCL-cellulose by a new route

    Directory of Open Access Journals (Sweden)

    K. L. Wang

    2017-12-01

    Full Text Available A new and convenient route to the regiocontrolled synthesis of a cellulose-based derivate copolymer (2,3-di-O-polycaprolactone-cellulose grafting ε-caprolactone (ε-CL from α-cellulose, cellulose-graft-polycaprolactone (cellulose-g-PCL, by a classical ring-opening polymerization (ROP reaction, using stannous octoate (Sn(Oct2 as catalyst, in 68% concentration of zinc chloride aqueous solution at 120 °C was presented. By controlling the hydroxyl of cellulose/ε-CL, catalyst/monomer ratio and the reaction time, the molecular architecture of the copolymers can be altered. The solubility of cellulose in zinc chloride aqueous was indicated by UV/VIS spectrometer and rheological measurements. The structures and thermal properties of cellulose-g-polycaprolactone copolymers were characterized using Fourier Transform Infrared (FT-IR, Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR, X-ray Diffraction (XRD, Thermogravimetric Analysis (TGA, Differential Scanning Calorimetry (DSC and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The interesting results confirm that zinc chloride solution can break the intra-molecular hydrogen bonds of cellulose selectively (not only O3H···O5, but also O2H···O6, and has no effect on the inter-molecular hydrogen bonds (O6H···O3. And the grafting reactivity of hydroxyl on cellulose is C2–OH > C3–OH >> C6–OH in zinc chloride solution, and this is clearly different from other researches. Most importantly, this work confirms that the method to regiocontrolled synthesis cellulose-based derivative polymers by regiobreaking hydrogen bonds is feasible. It is strongly believed that the new discovery may give a novel, environmental, simple and inexpensive method to modify cellulose chemically with various side chains grafted on a given hydroxyl, through liberating hydroxyl as reactive group from hydrogen bonds broken selectively by different solvents.

  17. Method of saccharifying cellulose

    Science.gov (United States)

    Johnson, E.A.; Demain, A.L.; Madia, A.

    1983-05-13

    A method is disclosed of saccharifying cellulose by incubation with the cellulase of Clostridium thermocellum in a broth containing an efficacious amount of thiol reducing agent. Other incubation parameters which may be advantageously controlled to stimulate saccharification include the concentration of alkaline earth salts, pH, temperature, and duration. By the method of the invention, even native crystalline cellulose such as that found in cotton may be completely saccharified.

  18. High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

    KAUST Repository

    Ali, Ola

    2013-05-01

    Regenerated cellulose (RC) membranes are extensively used in medical and pharmaceutical separation processes due to their biocompatibility, low fouling tendency and solvent resistant properties. They typically possess ultrafiltration and microfiltration separation characteristics, but recently, there have been attempts to widen their pool of applications in nanofiltration processes. In this work, a novel method for preparing high performance composite RC membranes was developed. These membranes reveal molecular weight cut-offs (MWCO) of less than 250 daltons, which possibly put them ahead of all commercial RC membranes and in competition with high performance nanofiltration membranes. The membranes were prepared by acidic hydrolysis of dip-coated trimethylsilyl cellulose (TMSC) films. TMSC, with a degree of silylation (DS) of 2.8, was prepared from microcrystalline cellulose by reaction with hexamethyldisilazane under the homogeneous conditions of LiCl/DMAC solvent system. Effects of parameters, such as coating solution concentration and drying rates, were investigated. It was concluded that higher TMSC concentrations as well as higher solvent evaporation rates favor better MWCOs, mainly due to increase in the selective layer thickness. Successful cross-linking of prepared membranes with glyoxal solutions, in the presence of boric acid as a catalyst, resulted in MWCOs less than 250 daltons. The suitability of this crosslinking reaction for large scale productions was already proven in the manufacturing of durable-press fabrics. For us, the inexpensive raw materials as well as the low reaction times and temperatures were of interest. Moreover, the non-toxic nature of glyoxal is a key advantage in medical and pharmaceutical applications. The membranes prepared in this work are strong candidates for separation of small organic solutes from organic solvents streams in pharmaceutical industries. Their hydrophilicity, compared to typical nanofiltration membranes, offer

  19. Large-scale additive manufacturing with bioinspired cellulosic materials.

    Science.gov (United States)

    Sanandiya, Naresh D; Vijay, Yadunund; Dimopoulou, Marina; Dritsas, Stylianos; Fernandez, Javier G

    2018-06-05

    Cellulose is the most abundant and broadly distributed organic compound and industrial by-product on Earth. However, despite decades of extensive research, the bottom-up use of cellulose to fabricate 3D objects is still plagued with problems that restrict its practical applications: derivatives with vast polluting effects, use in combination with plastics, lack of scalability and high production cost. Here we demonstrate the general use of cellulose to manufacture large 3D objects. Our approach diverges from the common association of cellulose with green plants and it is inspired by the wall of the fungus-like oomycetes, which is reproduced introducing small amounts of chitin between cellulose fibers. The resulting fungal-like adhesive material(s) (FLAM) are strong, lightweight and inexpensive, and can be molded or processed using woodworking techniques. We believe this first large-scale additive manufacture with ubiquitous biological polymers will be the catalyst for the transition to environmentally benign and circular manufacturing models.

  20. Pyrolytic sugars from cellulosic biomass

    Science.gov (United States)

    Kuzhiyil, Najeeb

    Sugars are the feedstocks for many promising advanced cellulosic biofuels. Traditional sugars derived from starch and sugar crops are limited in their availability. In principle, more plentiful supply of sugars can be obtained from depolymerization of cellulose, the most abundant form of biomass in the world. Breaking the glycosidic bonds between the pyranose rings in the cellulose chain to liberate glucose has usually been pursued by enzymatic hydrolysis although a purely thermal depolymerization route to sugars is also possible. Fast pyrolysis of pure cellulose yields primarily levoglucosan, an anhydrosugar that can be hydrolyzed to glucose. However, naturally occurring alkali and alkaline earth metals (AAEM) in biomass are strongly catalytic toward ring-breaking reactions that favor formation of light oxygenates over anhydrosugars. Removing the AAEM by washing was shown to be effective in increasing the yield of anhydrosugars; but this process involves removal of large amount of water from biomass that renders it energy intensive and thereby impractical. In this work passivation of the AAEM (making them less active or inactive) using mineral acid infusion was explored that will increase the yield of anhydrosugars from fast pyrolysis of biomass. Mineral acid infusion was tried by previous researchers, but the possibility of chemical reactions between infused acid and AAEM in the biomass appears to have been overlooked, possibly because metal cations might be expected to already be substantially complexed to chlorine or other strong anions that are found in biomass. Likewise, it appears that previous researchers assumed that as long as AAEM cations were in the biomass, they would be catalytically active regardless of the nature of their complexion with anions. On the contrary, we hypothesized that AAEM can be converted to inactive or less active salts using mineral acids. Various biomass feedstocks were infused with mineral (hydrochloric, nitric, sulfuric and

  1. Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

    KAUST Repository

    Puspasari, Tiara

    2018-05-01

    Cellulose has emerged as an indispensable membrane material due to its abundant availability, low cost, fascinating physiochemical properties and environment benignancy. However, it is believed that the potential of this polymer is not fully explored yet due to its insolubility in the common organic solvents, encouraging the use of derivatization-regeneration method as a viable alternative to the direct dissolution in exotic or reactive solvents. In this work, we use trimethylsilyl cellulose (TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome solvents used in the one step cellulose processing are avoided. This derivative is prepared from cellulose by the known silylation reaction. The complete transformation of TMSC back into cellulose after the membrane formation is carried out by vapor-phase acid treatment, which is simple, scalable and reproducible. This process along with the initial TMSC concentration determines the membrane sieving characteristics. Unlike the typical regenerated cellulose membranes with meso- or macropores, membranes regenerated from TMSC display micropores suitable for the selective separation of nanomolecules in aqueous and organic solvent nanofiltration. The membranes introduced in this thesis represent the first polymeric membranes ever reported for highly selective separation of similarly sized small organic molecules based on charge and size differences with outstanding fluxes. Owing to its strong hydrophilic and amorphous character, the membranes also demonstrate excellent air-dehumidification performance as compared to previously reported thin film composite membranes. Moreover, the use of TMSC enables the creation of the previously unfeasible cellulose–polydimethylsiloxane (PDMS) and cellulose–polyethyleneimine (PEI) blend membranes

  2. Physicochemical analysis of cellulose from microalgae ...

    African Journals Online (AJOL)

    USER

    2016-06-15

    Jun 15, 2016 ... The extraction method of algae cellulose was a modification of ... triplicate. Characterization of cellulose. Analysis of ... The current analysis of the cellulose extracted .... Cellulose nanomaterials review: structure, properties and.

  3. Single-molecule study of oxidative enzymatic deconstruction of cellulose.

    Science.gov (United States)

    Eibinger, Manuel; Sattelkow, Jürgen; Ganner, Thomas; Plank, Harald; Nidetzky, Bernd

    2017-10-12

    LPMO (lytic polysaccharide monooxygenase) represents a unique paradigm of cellulosic biomass degradation by an oxidative mechanism. Understanding the role of LPMO in deconstructing crystalline cellulose is fundamental to the enzyme's biological function and will help to specify the use of LPMO in biorefinery applications. Here we show with real-time atomic force microscopy that C1 and C4 oxidizing types of LPMO from Neurospora crassa (NcLPMO9F, NcLPMO9C) bind to nanocrystalline cellulose with high preference for the very same substrate surfaces that are also used by a processive cellulase (Trichoderma reesei CBH I) to move along during hydrolytic cellulose degradation. The bound LPMOs, however, are immobile during their adsorbed residence time ( ~ 1.0 min for NcLPMO9F) on cellulose. Treatment with LPMO resulted in fibrillation of crystalline cellulose and strongly ( ≥ 2-fold) enhanced the cellulase adsorption. It also increased enzyme turnover on the cellulose surface, thus boosting the hydrolytic conversion.Understanding the role of enzymes in biomass depolymerization is essential for the development of more efficient biorefineries. Here, the authors show by atomic force microscopy the real-time mechanism of cellulose deconstruction by lytic polysaccharide monooxygenases.

  4. The cellulose resource matrix.

    Science.gov (United States)

    Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

    2013-03-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

  5. Dose-dependent interaction between gemfibrozil and repaglinide in humans: strong inhibition of CYP2C8 with subtherapeutic gemfibrozil doses.

    Science.gov (United States)

    Honkalammi, Johanna; Niemi, Mikko; Neuvonen, Pertti J; Backman, Janne T

    2011-10-01

    Gemfibrozil 1-O-β-glucuronide inactivates CYP2C8 irreversibly. We investigated the effect of gemfibrozil dose on CYP2C8 activity in humans using repaglinide as a probe drug. In a randomized, five-phase crossover study, 10 healthy volunteers ingested 0.25 mg of repaglinide 1 h after different doses of gemfibrozil or placebo. Concentrations of plasma repaglinide, gemfibrozil, their metabolites, and blood glucose were measured. A single gemfibrozil dose of 30, 100, 300, and 900 mg increased the area under the concentration-time curve of repaglinide 1.8-, 4.5-, 6.7-, and 8.3-fold (P Gemfibrozil pharmacokinetics was characterized by a slightly more than dose-proportional increase in the area under the curve of gemfibrozil and its glucuronide. The gemfibrozil-repaglinide interaction could be mainly explained by gemfibrozil 1-O-β-glucuronide concentration-dependent, mechanism-based inhibition of CYP2C8, with a minor contribution by competitive inhibition of organic anion-transporting polypeptide 1B1 at the highest gemfibrozil dose. The findings are consistent with ∼50% inhibition of CYP2C8 already with a single 30-mg dose of gemfibrozil and >95% inhibition with 900 mg. In clinical drug-drug interaction studies, a single 900-mg dose of gemfibrozil can be used to achieve nearly complete inactivation of CYP2C8.

  6. Natural Composites: Cellulose Fibres and the related Performance of Composites

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2014-01-01

    Biobased materials are becoming of increasing interest as potential structural materials for the future. A useful concept in this context is the fibre reinforcement of materials by stiff and strong fibres. The biobased resources can contribute with cellulose fibres and biopolymers. This offers th...... in stiffness, on the packing ability of cellulose fibres and the related maximum fibre volume fraction in composites, on the moisture sorption of cellulose fibres and the related mass increase and (large) hygral strains induced, and on the mechanical performance of composites....

  7. The cellulose resource matrix

    NARCIS (Netherlands)

    Keijsers, E.R.P.; Yilmaz, G.; Dam, van J.E.G.

    2013-01-01

    The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where

  8. Bioconversion of cellulose to ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B; Mandenius, C F; Mattiasson, B; Nilsson, B; Axelsson, J P; Hagander, P

    1985-06-20

    Enzymatic hydrolysis of steam pretreated sallow gives highest yields of soluble sugars when hemicellulose is degraded already in the pretreatment step. The steam pretreatment equipment is rebuilt so that 75 g (dry matter) material instead of 7 g can be treated each time. The cellulose production has been increased 123% by the utilization of aqueous two-phase systems as compared to regular growth medium. The cellulase activity per gram of cellulose has been increased from 42 FPU in regular growth medium to 156 FPU in aqueous two-phase systems. Crude dextran can be used for enzyme production. Enzyme recovery up to 75% has been achieved by combining aqueous two-phase technique with membrane technique. Using the enzyme glucose isomerase in combination with S. cerevisiae theoretical yields in pentose fermentations have been achieved, with a product concentration of 60 g/L and a productivity of 2 g/L x h. Yeast and enzyme can be recirculated using membrane technique. Computer simulation shows that the rate equation for enzymatic hydrolysis with respect to inhibiting sugar concentrations can be used to interpolate with respect to sugar concentrations. Computer simulations show that hydrolysis experiments should focus on high substrate concentrations (>10%) using fed-batch technique and enzyme concentrations in the range of 2-8% in relation to substrate dry matter. The combined 'flow injection analysis', FIA, and enzyme reactor probe has been adapted to enzymatic saccarifications of sodium hydroxide pretreated sallow. The gas membrane sensor for ethanol has been utilized in simultaneous saccharification and fermentation of sodium hydroxide pretreated sallow. A literature study concerning pervaporation for ethanol up-grading has been made.(Author).

  9. Cellulose-dependent expression and antibacterial characteristics of surfactin from Bacillus subtilis HH2 isolated from the giant panda

    Science.gov (United States)

    Zhong, Zhijun; Su, Huaiyi; Li, Jin; Li, Haozhou; Feng, Fan; Lan, Jingchao; Zhang, Zhihe; Fu, Hualin; Hu, Yanchun; Cao, Suizhong; Chen, Weigang; Deng, Jiabo; Yu, Jianqiu; Zhang, Wenping

    2018-01-01

    Surfactin secreted by Bacillus subtilis can confer strong, diverse antipathogenic effects, thereby benefitting the host. Carbon source is an important factor for surfactin production. However, the mechanism that bacteria utilize cellulose, the most abundant substance in the intestines of herbivores, to produce surfactin remains unclear. Here, we used B. subtilis HH2, isolated from the feces of a giant panda, as a model to determine changes in surfactin expression in the presence of different concentrations of cellulose by quantitative polymerase chain reaction and high-performance liquid chromatography. We further investigated the antimicrobial effects of surfactin against three common intestinal pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella enterica) and its resistance to high temperature (60–121°C), pH (1–12), trypsin (100–300 μg/mL, pH 8), and pepsin (100–300 μg/mL, pH 2). The results showed that the surfactin expressed lowest in bacteria cultured in the presence of 1% glucose medium as the carbon source, whereas increased in an appropriate cellulose concentration (0.67% glucose and 0.33% cellulose). The surfactin could inhibit E. coli and Staphylococcus aureus, but did not affect efficiently for Salmonella enterica. The antibacterial ability of surfactin did not differ according to temperature (60–100°C), pH (2–11), trypsin (100–300 μg/mL), and pepsin (100–300 μg/mL; P > 0.05), but decreased significantly at extreme environments (121°C, pH 1 or 12; P < 0.05) compared with that in the control group (37°C, pH = 7, without any protease). In conclusion, our findings indicated that B. subtilis HH2 could increase surfactin expression in an appropriate cellulose environment and thus provide benefits to improve the intestinal health of herbivores. PMID:29385201

  10. Cellulose-dependent expression and antibacterial characteristics of surfactin from Bacillus subtilis HH2 isolated from the giant panda.

    Directory of Open Access Journals (Sweden)

    Ziyao Zhou

    Full Text Available Surfactin secreted by Bacillus subtilis can confer strong, diverse antipathogenic effects, thereby benefitting the host. Carbon source is an important factor for surfactin production. However, the mechanism that bacteria utilize cellulose, the most abundant substance in the intestines of herbivores, to produce surfactin remains unclear. Here, we used B. subtilis HH2, isolated from the feces of a giant panda, as a model to determine changes in surfactin expression in the presence of different concentrations of cellulose by quantitative polymerase chain reaction and high-performance liquid chromatography. We further investigated the antimicrobial effects of surfactin against three common intestinal pathogens (Escherichia coli, Staphylococcus aureus, and Salmonella enterica and its resistance to high temperature (60-121°C, pH (1-12, trypsin (100-300 μg/mL, pH 8, and pepsin (100-300 μg/mL, pH 2. The results showed that the surfactin expressed lowest in bacteria cultured in the presence of 1% glucose medium as the carbon source, whereas increased in an appropriate cellulose concentration (0.67% glucose and 0.33% cellulose. The surfactin could inhibit E. coli and Staphylococcus aureus, but did not affect efficiently for Salmonella enterica. The antibacterial ability of surfactin did not differ according to temperature (60-100°C, pH (2-11, trypsin (100-300 μg/mL, and pepsin (100-300 μg/mL; P > 0.05, but decreased significantly at extreme environments (121°C, pH 1 or 12; P < 0.05 compared with that in the control group (37°C, pH = 7, without any protease. In conclusion, our findings indicated that B. subtilis HH2 could increase surfactin expression in an appropriate cellulose environment and thus provide benefits to improve the intestinal health of herbivores.

  11. Biocomposites of nanofibrillated cellulose, polypyrrole, and silver nanoparticles with electroconductive and antimicrobial properties.

    Science.gov (United States)

    Bober, Patrycja; Liu, Jun; Mikkonen, Kirsi S; Ihalainen, Petri; Pesonen, Markus; Plumed-Ferrer, Carme; von Wright, Atte; Lindfors, Tom; Xu, Chunlin; Latonen, Rose-Marie

    2014-10-13

    In this work, flexible and free-standing composite films of nanofibrillated cellulose/polypyrrole (NFC/PPy) and NFC/PPy-silver nanoparticles (NFC/PPy-Ag) have been synthesized for the first time via in situ one-step chemical polymerization and applied in potential biomedical applications. Incorporation of NFC into PPy significantly improved its film formation ability resulting in composite materials with good mechanical and electrical properties. It is shown that the NFC/PPy-Ag composite films have strong inhibition effect against the growth of Gram-positive bacteria, e.g., Staphylococcus aureus. The electrical conductivity and strong antimicrobial activity makes it possible to use the silver composites in various applications aimed at biomedical treatments and diagnostics. Additionally, we report here the structural and morphological characterization of the composite materials with Fourier-transform infrared spectroscopy, atomic force microscopy, and scanning and transmission electron microscopy techniques.

  12. The fate of 131I-17-iodoheptadecanoic acid during lactate loading: Its oxidation is strongly inhibited in favor of its esterification

    International Nuclear Information System (INIS)

    Duwel, C.M.B.; Visser, F.C.; Eenige, M.J. van; Roos, J.P.; Hollander, W. den

    1990-01-01

    The influence of lactate loading on fatty acid metabolism (pH = 7.4) by the normal canine heart was investigated radiochemically using the radioiodinated fatty acid 131 I-17-iodoheptadecanoic acid ( 131 I-17-HDA). Fatty acid metabolism was studied during control conditions (n = 8) and after lactate loading (n = 7). In the canine heart total myocardial 131 I-17-HDA radioactivity (uptake) was not changed during the lactate intervention. The oxidation decreased fivefold (measured as free 131 I-iodide ion) from 70% to 14% (p 131 I-17-HDA was mainly stored in the triglycerides and phosphoglycerides. These results suggest that lactate inhibits cardiac 131 I-HDA oxidation. (orig.) [de

  13. Synthesis and characterization of cellulose derivatives obtained from bacterial cellulose

    International Nuclear Information System (INIS)

    Oliveira, Rafael L. de; Barud, Hernane; Ribeiro, Sidney J.L.; Messaddeq, Younes

    2011-01-01

    The chemical modification of cellulose leads to production of derivatives with different properties from those observed for the original cellulose, for example, increased solubility in more traditional solvents. In this work we synthesized four derivatives of cellulose: microcrystalline cellulose, cellulose acetate, methylcellulose and carboxymethylcellulose using bacterial cellulose as a source. These were characterized in terms of chemical and structural changes by examining the degree of substitution (DS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy - NMR 13 C. The molecular weight and degree of polymerization were evaluated by viscometry. The characterization of the morphology of materials and thermal properties were performed with the techniques of X-ray diffraction, electron microscopy images, differential scanning calorimetry (DSC) and thermogravimetric analysis. (author)

  14. Glucose production for cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S; Karube, I

    1977-04-16

    Glucose was produced from cellulose by passing a cellulose solution through a column of an immobilized cellulase which was prepared by coating an inorganic carrier such as macadam or stainless steel beads with collagen containing the cellulase. Thus, 4 mL of 5% cellulase T-AP (60,000 units/g) solution was dissolved in 100 g of 0.9% collagen solution and the solution mixed with 60 g of macadam (diam. = 0.5 to 1.5 mm) and stirred for 10 min. The treated beads were dried in air at 10/sup 0/ to yield an immobilized enzyme retaining 64% of its activity. Through a column (0.8 x 20 cm) packed with 3 g of the immobilized enzyme, 100 mL of 0.33% Avicel SF solution was circulated at 26.4 mL/min at 30/sup 0/ for 60 h. The Avicel SF conversion to glucose was 23%.

  15. High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

    KAUST Repository

    Ali, Ola

    2013-01-01

    Regenerated cellulose (RC) membranes are extensively used in medical and pharmaceutical separation processes due to their biocompatibility, low fouling tendency and solvent resistant properties. They typically possess ultrafiltration

  16. Structure and dynamics of a complex of cellulose with EDA: insights into the action of amines on cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Daisuke [ORNL; Nishiyama, Yoshiharu [Centre de Recherches sur les Macromolecules Vegetales (CERMAV-CNRS); Petridis, Loukas [ORNL; Parthasarathi, R. [Los Alamos National Laboratory (LANL); Gnanakaran, S [Los Alamos National Laboratory (LANL); Forsyth, V. T. [Institut Laue Langevin and Keele University; Wada, Masahisa [University of Tokyo, Japan; Langan, Paul [ORNL

    2013-01-01

    The neutron structure of a complex of EDA with cellulose has been determined to reveal the location of hydrogen atoms involved in hydrogen bonding. EDA disrupts the hydrogen bonding pattern of naturally occurring cellulose by accepting a strong hydrogen bond from the O6 hydroxymethyl group as the conformation of this group is rotated from tg to gt. The O3-H O5 intrachain hydrogen bond commonly found in cellulose allomorphs is observed to be disordered in the neutron structure, and quantum chemistry and molecular dynamics calculations show that O3 prefers to donate to EDA. The hydrogen bonding arrangement is highly dynamic with bonds continually being formed and broken thus explaining the difficulty in locating all of the hydrogen atoms in the neutron scattering density maps. Comparison with other polysaccharide-amine complexes supports a common underlying mechanism for amine disruption of cellulose.

  17. Nanofibrillated Cellulose Surface Modification: A Review

    Directory of Open Access Journals (Sweden)

    Julien Bras

    2013-05-01

    Full Text Available Interest in nanofibrillated cellulose (NFC has increased notably over recent decades. This bio-based nanomaterial has been used essentially in bionanocomposites or in paper thanks to its high mechanical reinforcement ability or barrier property respectively. Its nano-scale dimensions and its capacity to form a strong entangled nanoporous network have encouraged the emergence of new high-value applications. It is worth noting that chemical surface modification of this material can be a key factor to achieve a better compatibility with matrices. In order to increase the compatibility in different matrices or to add new functions, surface chemical modification of NFC appears to be the prior choice to conserve its intrinsic nanofibre properties. In this review, the authors have proposed for the first time an overview of all chemical grafting strategies used to date on nanofibrillated cellulose with focus on surface modification such as physical adsorption, molecular grafting or polymer grafting.

  18. Cellulose conversion of corn pericarp without pretreatment.

    Science.gov (United States)

    Kim, Daehwan; Orrego, David; Ximenes, Eduardo A; Ladisch, Michael R

    2017-12-01

    We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5mg/g and gave 98% cellulose conversion in 72h. However, for double the amount of enzyme from Trichoderma reesei, which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 7-methylguanosine diphosphate (m(7)GDP) is not hydrolyzed but strongly bound by decapping scavenger (DcpS) enzymes and potently inhibits their activity.

    Science.gov (United States)

    Wypijewska, Anna; Bojarska, Elzbieta; Lukaszewicz, Maciej; Stepinski, Janusz; Jemielity, Jacek; Davis, Richard E; Darzynkiewicz, Edward

    2012-10-09

    Decapping scavenger (DcpS) enzymes catalyze the cleavage of a residual cap structure following 3' → 5' mRNA decay. Some previous studies suggested that both m(7)GpppG and m(7)GDP were substrates for DcpS hydrolysis. Herein, we show that mononucleoside diphosphates, m(7)GDP (7-methylguanosine diphosphate) and m(3)(2,2,7)GDP (2,2,7-trimethylguanosine diphosphate), resulting from mRNA decapping by the Dcp1/2 complex in the 5' → 3' mRNA decay, are not degraded by recombinant DcpS proteins (human, nematode, and yeast). Furthermore, whereas mononucleoside diphosphates (m(7)GDP and m(3)(2,2,7)GDP) are not hydrolyzed by DcpS, mononucleoside triphosphates (m(7)GTP and m(3)(2,2,7)GTP) are, demonstrating the importance of a triphosphate chain for DcpS hydrolytic activity. m(7)GTP and m(3)(2,2,7)GTP are cleaved at a slower rate than their corresponding dinucleotides (m(7)GpppG and m(3)(2,2,7)GpppG, respectively), indicating an involvement of the second nucleoside for efficient DcpS-mediated digestion. Although DcpS enzymes cannot hydrolyze m(7)GDP, they have a high binding affinity for m(7)GDP and m(7)GDP potently inhibits DcpS hydrolysis of m(7)GpppG, suggesting that m(7)GDP may function as an efficient DcpS inhibitor. Our data have important implications for the regulatory role of m(7)GDP in mRNA metabolic pathways due to its possible interactions with different cap-binding proteins, such as DcpS or eIF4E.

  20. Adenovirally delivered shRNA strongly inhibits Na+-Ca2+ exchanger expression but does not prevent contraction of neonatal cardiomyocytes.

    Science.gov (United States)

    Hurtado, Cecilia; Ander, Bradley P; Maddaford, Thane G; Lukas, Anton; Hryshko, Larry V; Pierce, Grant N

    2005-04-01

    The cardiac Na(+)-Ca(2+) exchanger (NCX1) is the main mechanism for Ca(2+) efflux in the heart and is thought to serve an essential role in cardiac excitation-contraction (E-C) coupling. The demonstration that an NCX1 gene knock-out is embryonic lethal provides further support for this essential role. However, a recent report employing the Cre/loxP technique for cardiac specific knock-out of NCX1 has revealed that cardiac function is remarkably preserved in these mice, which survived to adulthood. This controversy highlights the necessity for further investigation of NCX1 function in the heart. In this study, we report on a novel approach for depletion of NCX1 in postnatal rat myocytes that utilizes RNA interference (RNAi), administered with high efficiency via adenoviral transfection. Depletion of NCX1 was confirmed by immunocytochemical detection, Western blots and radioisotopic assays of Na(+)-Ca(2+) exchange activity. Exchanger expression was inhibited by up to approximately 94%. Surprisingly, spontaneous beating of these cardiomyocytes was still maintained, although at a lower frequency. Electrical stimulation could elicit a normal beating rhythm, although NCX depleted cells exhibited a depressed Ca(2+) transient amplitude, a depressed rate of Ca(2+) rise and decline, elevated diastolic [Ca(2+)], and shorter action potentials. We also observed a compensatory increase in sarcolemmal Ca(2+) pump expression. Our data support an important, though non-essential, role for the NCX1 in E-C coupling in these neonatal heart cells. Furthermore, this approach provides a valuable means for assessing the role of NCX1 and could be utilized to examine other cardiac proteins in physiological and pathological studies.

  1. Drug-loaded Cellulose Acetate and Cellulose Acetate Butyrate Films ...

    African Journals Online (AJOL)

    The purpose of this research work was to evaluate the contribution of formulation variables on release properties of matrix type ocular films containing chloramphenicol as a model drug. This study investigated the use of cellulose acetate and cellulose acetate butyrate as film-forming agents in development of ocular films.

  2. Radiation degradation of cellulose

    International Nuclear Information System (INIS)

    Leonhardt, J.; Arnold, G.; Baer, M.; Langguth, H.; Gey, M.; Huebert, S.

    1985-01-01

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20% up to about 80%. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given. (author)

  3. Cellulose synthase complex organization and cellulose microfibril structure.

    Science.gov (United States)

    Turner, Simon; Kumar, Manoj

    2018-02-13

    Cellulose consists of linear chains of β-1,4-linked glucose units, which are synthesized by the cellulose synthase complex (CSC). In plants, these chains associate in an ordered manner to form the cellulose microfibrils. Both the CSC and the local environment in which the individual chains coalesce to form the cellulose microfibril determine the structure and the unique physical properties of the microfibril. There are several recent reviews that cover many aspects of cellulose biosynthesis, which include trafficking of the complex to the plasma membrane and the relationship between the movement of the CSC and the underlying cortical microtubules (Bringmann et al. 2012 Trends Plant Sci. 17 , 666-674 (doi:10.1016/j.tplants.2012.06.003); Kumar & Turner 2015 Phytochemistry 112 , 91-99 (doi:10.1016/j.phytochem.2014.07.009); Schneider et al. 2016 Curr. Opin. Plant Biol. 34 , 9-16 (doi:10.1016/j.pbi.2016.07.007)). In this review, we will focus on recent advances in cellulose biosynthesis in plants, with an emphasis on our current understanding of the structure of individual catalytic subunits together with the local membrane environment where cellulose synthesis occurs. We will attempt to relate this information to our current knowledge of the structure of the cellulose microfibril and propose a model in which variations in the structure of the CSC have important implications for the structure of the cellulose microfibril produced.This article is part of a discussion meeting issue 'New horizons for cellulose nanotechnology'. © 2017 The Author(s).

  4. Cellulose binding domain fusion proteins

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1998-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  5. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  6. Occurrence of Cellulose-Producing Gluconacetobacter spp. in Fruit Samples and Kombucha Tea, and Production of the Biopolymer.

    Science.gov (United States)

    Neera; Ramana, Karna Venkata; Batra, Harsh Vardhan

    2015-06-01

    Cellulose producing bacteria were isolated from fruit samples and kombucha tea (a fermented beverage) using CuSO4 solution in modified Watanabe and Yamanaka medium to inhibit yeasts and molds. Six bacterial strains showing cellulose production were isolated and identified by 16S rRNA gene sequencing as Gluconacetobacter xylinus strain DFBT, Ga. xylinus strain dfr-1, Gluconobacter oxydans strain dfr-2, G. oxydans strain dfr-3, Acetobacter orientalis strain dfr-4, and Gluconacetobacter intermedius strain dfr-5. All the cellulose-producing bacteria were checked for the cellulose yield. A potent cellulose-producing bacterium, i.e., Ga. xylinus strain DFBT based on yield (cellulose yield 5.6 g/L) was selected for further studies. Cellulose was also produced in non- conventional media such as pineapple juice medium and hydrolysed corn starch medium. A very high yield of 9.1 g/L cellulose was obtained in pineapple juice medium. Fourier transform infrared spectrometer (FT-IR) analysis of the bacterial cellulose showed the characteristic peaks. Soft cellulose with a very high water holding capacity was produced using limited aeration. Scanning electron microscopy (SEM) was used to analyze the surface characteristics of normal bacterial cellulose and soft cellulose. The structural analysis of the polymer was performed using (13)C solid-state nuclear magnetic resonance (NMR). More interfibrillar space was observed in the case of soft cellulose as compared to normal cellulose. This soft cellulose can find potential applications in the food industry as it can be swallowed easily without chewing.

  7. Saccharification of cellulose by acetolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T; Yamanaka, S; Takinami, K

    1978-01-01

    For saccharification of cellulose, an acetolysis method using assimilable acid with a microorganism was applied. Based on this method, a new method which gave totally assimilable products was established. The rigid crystalline structure of cellulose was disrupted by acetolysis with 2-2.5 times as much acetic anhydride as cellulose on a weight basis and 1 N sulfuric acid as a catalyst. Then for cleavage of O-acetyl ester and glycosidic bonds, the resulting amorphous acetolysate of cellulose could easily be hydrolyzed by heating in 1 N sulfuric acid at 120/sup 0/C for 1-1.5 h without over-disruption of glucose. Ninety-eight % of the cellulose used was recovered in the form of hydrolysate having about 30% saccharide concentration. The hydrolysate obtained was composed of 74% glucose, 13% cellobiose and 11% mono-O-acetyl glucose on a weight basis.

  8. Expression of a single siRNA against a conserved region of NP gene strongly inhibits in vitro replication of different Influenza A virus strains of avian and swine origin.

    Science.gov (United States)

    Stoppani, Elena; Bassi, Ivan; Dotti, Silvia; Lizier, Michela; Ferrari, Maura; Lucchini, Franco

    2015-08-01

    Influenza A virus is the principal agent responsible of the respiratory tract's infections in humans. Every year, highly pathogenic and infectious strains with new antigenic assets appear, making ineffective vaccines so far developed. The discovery of RNA interference (RNAi) opened the way to the progress of new promising drugs against Influenza A virus and also to the introduction of disease resistance traits in genetically modified animals. In this paper, we show that Madin-Darby Canine Kidney (MDCK) cell line expressing short hairpin RNAs (shRNAs) cassette, designed on a specific conserved region of the nucleoprotein (NP) viral genome, can strongly inhibit the viral replication of four viral strains sharing the target sequence, reducing the viral mRNA respectively to 2.5×10(-4), 7.5×10(-5), 1.7×10(-3), 1.9×10(-4) compared to the control, as assessed by real-time PCR. Moreover, we demonstrate that during the challenge with a viral strain bearing a single mismatch on the target sequence, although a weaker inhibition is observed, viral mRNA is still lowered down to 1.2×10(-3) folds in the shRNA-expressing clone compared to the control, indicating a broad potential use of this approach. In addition, we developed a highly predictive and fast screening test of siRNA sequences based on dual-luciferase assay, useful for the in vitro prediction of the potential effect of viral inhibition. In conclusion, these findings reveal new siRNA sequences able to inhibit Influenza A virus replication and provide a basis for the development of siRNAs as prophylaxis and therapy for influenza infection both in humans and animals. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. <strong>Mini-project>

    DEFF Research Database (Denmark)

    Katajainen, Jyrki

    2008-01-01

    In this project the goal is to develop the safe * family of containers for the CPH STL. The containers to be developed should be safer and more reliable than any of the existing implementations. A special focus should be put on strong exception safety since none of the existing prototypes available...

  10. Evaluating the effect of potassium on cellulose pyrolysis reaction kinetics

    International Nuclear Information System (INIS)

    Trendewicz, Anna; Evans, Robert; Dutta, Abhijit; Sykes, Robert; Carpenter, Daniel; Braun, Robert

    2015-01-01

    This paper proposes modifications to an existing cellulose pyrolysis mechanism in order to include the effect of potassium on product yields and composition. The changes in activation energies and pre-exponential factors due to potassium were evaluated based on the experimental data collected from pyrolysis of cellulose samples treated with different levels of potassium (0–1% mass fraction). The experiments were performed in a pyrolysis reactor coupled to a molecular beam mass spectrometer (MBMS). Principal component analysis (PCA) performed on the collected data revealed that cellulose pyrolysis products could be divided into two groups: anhydrosugars and other fragmentation products (hydroxyacetaldehyde, 5-hydroxymethylfurfural, acetyl compounds). Multivariate curve resolution (MCR) was used to extract the time resolved concentration score profiles of principal components. Kinetic tests revealed that potassium apparently inhibits the formation of anhydrosugars and catalyzes char formation. Therefore, the oil yield predicted at 500 ° C decreased from 87.9% from cellulose to 54.0% from cellulose with 0.5% mass fraction potassium treatment. The decrease in oil yield was accompanied by increased yield of char and gases produced via a catalyzed dehydration reaction. The predicted char and gas yield from cellulose were 3.7% and 8.4%, respectively. Introducing 0.5% mass fraction potassium treatment resulted in an increase of char yield to 12.1% and gas yield to 33.9%. The validation of the cellulose pyrolysis mechanism with experimental data from a fluidized-bed reactor, after this correction for potassium, showed good agreement with our results, with differences in product yields of up to 5%

  11. On the determination of crystallinity and cellulose content in plant fibres

    DEFF Research Database (Denmark)

    Thygesen, Anders; Oddershede, Jette; Lilholt, Hans

    2005-01-01

    A comparative study of cellulose crystallinity based on the sample crystallinity and the cellulose content in plant fibres was performed for samples of different origin. Strong acid hydrolysis was found superior to agricultural fibre analysis and comprehensive plant fibre analysis for a consistent...... determination of the cellulose content. Crystallinity determinations were based on X-ray powder diffraction methods using side-loaded samples in reflection (Bragg-Brentano) mode. Rietveld refinements based on the recently published crystal structure of cellulose I beta followed by integration of the crystalline...... and 60 - 70 g/ 100 g cellulose in wood based fibres. These findings are significant in relation to strong fibre composites and bio-ethanol production....

  12. Cyclic diguanylic acid and cellulose synthesis in Agrobacterium tumefaciens

    International Nuclear Information System (INIS)

    Amikam, D.; Benziman, M.

    1989-01-01

    The occurrence of the novel regulatory nucleotide bis(3',5')-cyclic diguanylic acid (c-di-GMP) and its relation to cellulose biogenesis in the plant pathogen Agrobacterium tumefaciens was studied. c-di-GMP was detected in acid extracts of 32 P-labeled cells grown in various media, and an enzyme responsible for its formation from GTP was found to be present in cell-free preparations. Cellulose synthesis in vivo was quantitatively assessed with [ 14 C]glucose as a tracer. The organism produced cellulose during growth in the absence of plant cells, and this capacity was retained in resting cells. Synthesis of a cellulosic product from UDP-glucose in vitro with membrane preparations was markedly stimulated by c-di-GMP and its precursor GTP and was further enhanced by Ca2+. The calcium effect was attributed to inhibition of a c-di-GMP-degrading enzyme shown to be present in the cellulose synthase-containing membranes

  13. Strong interactions

    International Nuclear Information System (INIS)

    Froissart, Marcel

    1976-01-01

    Strong interactions are introduced by their more obvious aspect: nuclear forces. In hadron family, the nucleon octet, OMEGA - decuplet, and quark triply are successively considered. Pion wave having been put at the origin of nuclear forces, low energy phenomena are described, the force being explained as an exchange of structure corresponding to a Regge trajectory in a variable rotating state instead of the exchange of a well defined particle. At high energies the concepts of pomeron, parton and stratons are introduced, pionization and fragmentation are briefly differentiated [fr

  14. Non-enzymatic depolymerization of cotton cellulose by fungal mimicking metabolites

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jensen, Bo

    2011-01-01

    peroxide, iron, and oxalic acid. The former two are involved in the Fenton reaction in which they react to form hydroxyl radicals, which cause an accelerated depolymerization in cotton cellulose. We found the same reaction to be caused by both iron Fe3+ and Fe2+. A 10 mM oxalic acid solution showed...... significant depolymerization effect on cotton cellulose. An oxalic acid/sodium oxalate buffered pH gradient had an inhibitory effect on the reduction of cellulose polymers at increased pH values. The organic iron chelator, EDTA, was found to promote depolymerization of cellulose in combination with Fenton......’s reagents, but inhibited the effect of oxalic acid in the absence of iron and hydrogen peroxide. Manganese was tested to see if metals other than iron could generate a significant impact on the degree of polymerization (DP) in cotton cellulose. Depolymerizing properties comparable to iron were seen...

  15. 21 CFR 573.420 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl cellulose. 573.420 Section 573.420 Food and... Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether containing...

  16. Evaluation of microcrystalline cellulose modifed from alpha ...

    African Journals Online (AJOL)

    Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss ...

  17. 21 CFR 172.868 - Ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl cellulose. 172.868 Section 172.868 Food and... Multipurpose Additives § 172.868 Ethyl cellulose. The food additive ethyl cellulose may be safely used in food in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  18. Radiation degradation of cellulose

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Arnold, G.; Baer, M.; Gey, M.; Hubert, S.; Langguth, H.

    1984-01-01

    The application of straw and other cellulose polymers as feedstuff for ruminants is limited by its low digestibility. During recent decades it was attempted to increase the digestibility of straw by several chemical and physical methods. In this work some results of the degradation of gamma and electron treated wheat straw are reported. Complex methods of treatment (e.g. radiation influence and influence of lyes) are taken into consideration. In vitro-experiments with radiation treated straw show that the digestibility can be increased from 20% up to about 80%. A high pressure liquid chromatography method was used to analyze the hydrolysates. The contents of certain species of carbohydrates in the hydrolysates in dependence on the applied dose are given

  19. Effects of alkaline or liquid-ammonia treatment on crystalline cellulose: changes in crystalline structure and effects on enzymatic digestibility

    Directory of Open Access Journals (Sweden)

    Himmel Michael E

    2011-10-01

    Full Text Available Abstract Background In converting biomass to bioethanol, pretreatment is a key step intended to render cellulose more amenable and accessible to cellulase enzymes and thus increase glucose yields. In this study, four cellulose samples with different degrees of polymerization and crystallinity indexes were subjected to aqueous sodium hydroxide and anhydrous liquid ammonia treatments. The effects of the treatments on cellulose crystalline structure were studied, in addition to the effects on the digestibility of the celluloses by a cellulase complex. Results From X-ray diffractograms and nuclear magnetic resonance spectra, it was revealed that treatment with liquid ammonia produced the cellulose IIII allomorph; however, crystallinity depended on treatment conditions. Treatment at a low temperature (25°C resulted in a less crystalline product, whereas treatment at elevated temperatures (130°C or 140°C gave a more crystalline product. Treatment of cellulose I with aqueous sodium hydroxide (16.5 percent by weight resulted in formation of cellulose II, but also produced a much less crystalline cellulose. The relative digestibilities of the different cellulose allomorphs were tested by exposing the treated and untreated cellulose samples to a commercial enzyme mixture (Genencor-Danisco; GC 220. The digestibility results showed that the starting cellulose I samples were the least digestible (except for corn stover cellulose, which had a high amorphous content. Treatment with sodium hydroxide produced the most digestible cellulose, followed by treatment with liquid ammonia at a low temperature. Factor analysis indicated that initial rates of digestion (up to 24 hours were most strongly correlated with amorphous content. Correlation of allomorph type with digestibility was weak, but was strongest with cellulose conversion at later times. The cellulose IIII samples produced at higher temperatures had comparable crystallinities to the initial cellulose I

  20. Acetone-based cellulose solvent.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; Heinze, Thomas

    2014-08-01

    Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Adsorption of TNT, DNAN, NTO, FOX7, and NQ onto cellulose, chitin, and cellulose triacetate. Insights from Density Functional Theory calculations

    Science.gov (United States)

    Todde, Guido; Jha, Sanjiv K.; Subramanian, Gopinath; Shukla, Manoj K.

    2018-02-01

    Insensitive munitions (IM) compounds such as DNAN (2,4-dinitroanisole), NTO (3-nitro-1,2,4-triazol-5-one), NQ (nitroguanidine), and FOX7 (1,1-diamino-2,2-dinitroethene) reduce the risk of accidental explosions due to shock and high temperature exposure. These compounds are being used as replacements for sensitive munition compounds such as TNT (2,4,6-trinitromethylbenzene) and RDX (1,3,5-hexahydro-1,3,5-trinitro-1,3,5-triazine). NTO and NQ in IM compounds are more soluble than TNT or RDX, hence they can easily spread in the environment and get dissolved if exposed to precipitation. DNAN solubility is comparable to TNT solubility. Cellulosic biomass, due to its abundance in the environment and its chemical structure, has a high probability of adsorbing these IM compounds, and thus, it is important to investigate the interactions between cellulose and cellulose like biopolymers (e.g. cellulose triacetate and chitin) with IM compounds. Using Density Functional Theory methods, we have studied the adsorption of TNT, DNAN, NTO, NQ, and FOX7 onto cellulose Iα and Iβ, chitin, and cellulose triacetate I (CTA I). Solvent effects on the adsorption were also investigated. Our results show that all contaminants are more strongly adsorbed onto chitin and cellulose Iα than onto CTA I and cellulose Iβ. Dispersion forces were found to be the predominant contribution to the adsorption energies of all contaminants.

  2. Preparation and characterization of nanocomposites of the carboxymethyl cellulose reinforced with cellulose nanocrystals

    International Nuclear Information System (INIS)

    Flauzino Neto, Wilson P.; Silverio, Hudson A.; Vieira, Julia G.; Silva, Heden C.; Rosa, Joyce R.; Pasquini, Daniel; Assuncao, Rosana M.N.

    2011-01-01

    Nanocrystals of cellulose (NCC) isolated from Eucalyptus urograndis Kraft pulp were used to prepare nanocomposites employing carboxymethyl cellulose (CMC) as matrix. The nanocrystals were isolated by hydrolysis with H 2 SO 4 64% solution, for 20 minutes at 45 deg C. The nanocrystals were characterized by X-ray diffraction to evaluate the crystallinity of them. The amount of NCC used in the preparation of nanocomposites varied from 0 to 15%. The nanocomposites were characterized by thermal and mechanical analysis. A large reinforcing effect of NCC on the CMC matrix was observed. With the incorporation of the NCC, the tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and heat resistance to decomposition increased subtle. The improvement in thermo-mechanical properties are attributed to strong interactions between nanoparticles and CMC matrix. (author)

  3. Cellulose microfibril structure: inspirations from plant diversity

    Science.gov (United States)

    Roberts, A. W.

    2018-03-01

    Cellulose microfibrils are synthesized at the plasma membrane by cellulose synthase catalytic subunits that associate to form cellulose synthesis complexes. Variation in the organization of these complexes underlies the variation in cellulose microfibril structure among diverse organisms. However, little is known about how the catalytic subunits interact to form complexes with different morphologies. We are using an evolutionary approach to investigate the roles of different catalytic subunit isoforms in organisms that have rosette-type cellulose synthesis complexes.

  4. Recent Strategies in Preparation of Cellulose Nanocrystals and Cellulose Nanofibrils Derived from Raw Cellulose Materials

    Directory of Open Access Journals (Sweden)

    Hongxiang Xie

    2018-01-01

    Full Text Available The recent strategies in preparation of cellulose nanocrystals (CNCs and cellulose nanofibrils (CNFs were described. CNCs and CNFs are two types of nanocelluloses (NCs, and they possess various superior properties, such as large specific surface area, high tensile strength and stiffness, low density, and low thermal expansion coefficient. Due to various applications in biomedical engineering, food, sensor, packaging, and so on, there are many studies conducted on CNCs and CNFs. In this review, various methods of preparation of CNCs and CNFs are summarized, including mechanical, chemical, and biological methods. The methods of pretreatment of cellulose are described in view of the benefits to fibrillation.

  5. WOOD CELLULOSE ACETATE MEMBRANE 179

    African Journals Online (AJOL)

    DR. AMINU

    2013-06-01

    Jun 1, 2013 ... 1988), cosmetics and food additives or pharmaceutical applications (Wellisch .... displaced by sample. Determination of percent α-, β- and γ–cellulose ..... addition, the smaller pore diameter would lead to a greater exclusion of ...

  6. Versatile High-Performance Regenerated Cellulose Membranes Prepared using Trimethylsilyl Cellulose as a Precursor

    KAUST Repository

    Puspasari, Tiara

    2018-01-01

    (TMSC), a highly soluble cellulose derivative, as a precursor for the fabrication of cellulose thin film composite membranes. TMSC is an attractive precursor to assemble thin cellulose films with good deposition behavior and film morphology; cumbersome

  7. Influence of the crystalline structure of cellulose on the production of ethanol from lignocellulose biomass

    Science.gov (United States)

    Smuga-Kogut, Małgorzata; Zgórska, Kazimiera; Szymanowska-Powałowska, Daria

    2016-01-01

    In recent years, much attention has been devoted to the possibility of using lignocellulosic biomass for energy. Bioethanol is a promising substitute for conventional fossil fuels and can be produced from straw and wood biomass. Therefore, the aim of this paper was to investigate the effect of 1-ethyl-3-methylimidazolium pretreatment on the structure of cellulose and the acquisition of reducing sugars and bioethanol from cellulosic materials. Material used in the study was rye straw and microcrystalline cellulose subjected to ionic liquid 1-ethyl-3-methylimidazolium pretreatment. The morphology of cellulose fibres in rye straw and microcrystalline cellulose was imaged prior to and after ionic liquid pretreatment. Solutions of ionic liquid-treated and untreated cellulosic materials were subjected to enzymatic hydrolysis in order to obtain reducing sugars, which constituted a substrate for alcoholic fermentation. An influence of the ionic liquid on the cellulose structure, accumulation of reducing sugars in the process of hydrolysis of this material, and an increase in ethanol amount after fermentation was observed. The ionic liquid did not affect cellulolytic enzymes negatively and did not inhibit yeast activity. The amount of reducing sugars and ethyl alcohol was higher in samples purified with 1-ethyl-3-methy-limidazolium acetate. A change in the supramolecular structure of cellulose induced by the ionic liquid was also observed.

  8. Bacterial cellulose/boehmite composites

    International Nuclear Information System (INIS)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L.; Caiut, Jose Mauricio A.

    2011-01-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  9. INFLUENCE OF CELLULOSE POLYMERIZATION DEGREE AND CRYSTALLINITY ON KINETICS OF CELLULOSE DEGRADATION

    OpenAIRE

    Edita Jasiukaitytė-Grojzdek,; Matjaž Kunaver,; Ida Poljanšek

    2012-01-01

    Cellulose was treated in ethylene glycol with p-toluene sulfonic acid monohydrate as a catalyst at different temperatures. At the highest treatment temperature (150 °C) liquefaction of wood pulp cellulose was achieved and was dependant on cellulose polymerization degree (DP). Furthermore, the rate of amorphous cellulose weight loss was found to increase with cellulose degree of polymerization, while the rate of crystalline cellulose weight loss was reciprocal to the size of the crystallites. ...

  10. Cellulose biosynthesis in higher plants

    Directory of Open Access Journals (Sweden)

    Krystyna Kudlicka

    2014-01-01

    Full Text Available Knowledge of the control and regulation of cellulose synthesis is fundamental to an understanding of plant development since cellulose is the primary structural component of plant cell walls. In vivo, the polymerization step requires a coordinated transport of substrates across membranes and relies on delicate orientations of the membrane-associated synthase complexes. Little is known about the properties of the enzyme complexes, and many questions about the biosynthesis of cell wall components at the cell surface still remain unanswered. Attempts to purify cellulose synthase from higher plants have not been successful because of the liability of enzymes upon isolation and lack of reliable in vitro assays. Membrane preparations from higher plant cells incorporate UDP-glucose into a glucan polymer, but this invariably turns out to be predominantly β -1,3-linked rather than β -1,4-linked glucans. Various hypotheses have been advanced to explain this phenomenon. One idea is that callose and cellulose-synthase systems are the same, but cell disruption activates callose synthesis preferentially. A second concept suggests that a regulatory protein as a part of the cellulose-synthase complex is rapidly degraded upon cell disruption. With new methods of enzyme isolation and analysis of the in vitro product, recent advances have been made in the isolation of an active synthase from the plasma membrane whereby cellulose synthase was separated from callose synthase.

  11. Decontamination of nuclear plant fluids with grafted celluloses

    International Nuclear Information System (INIS)

    Sandeaux, R.

    1991-01-01

    Ion exchange processes are specially well adapted techniques to solve some of nuclear plants problems, such as decontamination of the primary cooling circuit fluid and the cooling pool, because of the low concentration of the miscellaneous products to eliminate. Now the purification of these fluids is performed by using ion exchange resins. But recent researches show it is necessary to use more efficient techniques (1). The use of grafted celluloses should improve this process. The manufacturing of grafted celluloses was first performed with the collaboration of French Textile Institute and Morgane-Framatome (2). Cellulosic structure offers well known qualities for filtration: good micrometric retention, good mechanical behaviour, strong hydrophilic properties and high specific surface. Grafting was performed through a radiochemical process so as to bind polyelectrolytes on the backbone polymer. Compared to usual ion exchangers, these new materials offer different properties: - fast exchange kinetic - as uncrosslinked polymers, these grafted celluloses withstand better fouling with macroions or ionic complexes; - as they can be incinerated, radioactive wastes can be greatly reduced; - different commercial products of these grafted celluloses offer a wide range of possibilities for industrial uses [fr

  12. Ionic liquid processing of cellulose.

    Science.gov (United States)

    Wang, Hui; Gurau, Gabriela; Rogers, Robin D

    2012-02-21

    Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as 'g cellulose per mole of IL' or 'mol IL per mol hydroxyl in cellulose' to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process (142 references).

  13. Cellulose whisker/epoxy resin nanocomposites.

    Science.gov (United States)

    Tang, Liming; Weder, Christoph

    2010-04-01

    New nanocomposites composed of cellulose nanofibers or "whiskers" and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of approximately 10 and approximately 84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185-192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtures and subsequent curing. The whisker content was systematically varied between 4 and 24% v/v. Electron microscopy studies suggest that the whiskers are evenly dispersed within the epoxy matrix. Dynamic mechanical thermoanalysis revealed that the glass transition temperature (T(g)) of the materials was not significantly influenced by the incorporation of the cellulose filler. Between room temperature and 150 degrees C, i.e., below T(g), the tensile storage moduli (E') of the nanocomposites increased modestly, for example from 1.6 GPa for the neat polymer to 4.9 and 3.6 GPa for nanocomposites comprising 16% v/v tunicate or cotton whiskers. The relative reinforcement was more significant at 185 degrees C (i.e., above T(g)), where E' was increased from approximately 16 MPa (neat polymer) to approximately 1.6 GPa (tunicate) or approximately 215 MPa (cotton). The mechanical properties of the new materials are well-described by the percolation model and are the result of the formation of a percolating whisker network in which stress transfer is facilitated by strong interactions between the whiskers.

  14. Genome-Wide Association Study Reveals Novel Genes Associated with Culm Cellulose Content in Bread Wheat (Triticum aestivum, L.

    Directory of Open Access Journals (Sweden)

    Simerjeet Kaur

    2017-11-01

    Full Text Available Plant cell wall formation is a complex, coordinated and developmentally regulated process. Cellulose is the most dominant constituent of plant cell walls. Because of its paracrystalline structure, cellulose is the main determinant of mechanical strength of plant tissues. As the most abundant polysaccharide on earth, it is also the focus of cellulosic biofuel industry. To reduce culm lodging in wheat and for improved ethanol production, delineation of the variation for stem cellulose content could prove useful. We present results on the analysis of the stem cellulose content of 288 diverse wheat accessions and its genome-wide association study (GWAS. Cellulose concentration ranged from 35 to 52% (w/w. Cellulose content was normally distributed in the accessions around a mean and median of 45% (w/w. Genome-wide marker-trait association study using 21,073 SNPs helped identify nine SNPs that were associated (p < 1E-05 with cellulose content. Four strongly associated (p < 8.17E-05 SNP markers were linked to wheat unigenes, which included β-tubulin, Auxin-induced protein 5NG4, and a putative transmembrane protein of unknown function. These genes may be directly or indirectly involved in the formation of cellulose in wheat culms. GWAS results from this study have the potential for genetic manipulation of cellulose content in bread wheat and other small grain cereals to enhance culm strength and improve biofuel production.

  15. The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6

    OpenAIRE

    Endler, Anne; Schneider, Rene; Kesten, Christopher; Lampugnani, Edwin R.; Persson, Staffan

    2016-01-01

    Cellulose is a cell wall constituent that is essential for plant growth and development, and an important raw material for a range of industrial applications. Cellulose is synthesized at the plasma membrane by massive cellulose synthase (CesA) complexes that track along cortical microtubules in elongating cells of Arabidopsis through the activity of the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1). In a recent study we identified another family of proteins that also are associated with the ...

  16. Product inhibition of five Hypocrea jecorina cellulases

    DEFF Research Database (Denmark)

    Murphy, Leigh; Westh, Peter; Bohlin, Christina

    2013-01-01

    Product inhibition of cellulolytic enzymes has been deemed a critical factor in the industrial saccharification of cellulosic biomass. Several investigations have addressed this problem using crude enzyme preparations or commercial (mixed) cellulase products, but quantitative information...... on individual cellulases hydrolyzing insoluble cellulose remains insufficient. Such knowledge is necessary to pinpoint and quantify inhibitory weak-links in cellulose hydrolysis, but has proven challenging to come by. Here we show that product inhibition of mono-component cellulases hydrolyzing unmodified...... cellulose may be monitored by calorimetry. The key advantage of this approach is that it directly measures the rate of hydrolysis while being essentially blind to the background of added product. We investigated the five major cellulases from Hypocrea jecorina (anamorph: Tricoderma reesei), Cel7A (formerly...

  17. Longevity in vivo of primary cell wall cellulose synthases.

    Science.gov (United States)

    Hill, Joseph Lee; Josephs, Cooper; Barnes, William J; Anderson, Charles T; Tien, Ming

    2018-02-01

    Our work focuses on understanding the lifetime and thus stability of the three main cellulose synthase (CESA) proteins involved in primary cell wall synthesis of Arabidopsis. It had long been thought that a major means of CESA regulation was via their rapid degradation. However, our studies here have uncovered that AtCESA proteins are not rapidly degraded. Rather, they persist for an extended time in the plant cell. Plant cellulose is synthesized by membrane-embedded cellulose synthase complexes (CSCs). The CSC is composed of cellulose synthases (CESAs), of which three distinct isozymes form the primary cell wall CSC and another set of three isozymes form the secondary cell wall CSC. We determined the stability over time of primary cell wall (PCW) CESAs in Arabidopsis thaliana seedlings, using immunoblotting after inhibiting protein synthesis with cycloheximide treatment. Our work reveals very slow turnover for the Arabidopsis PCW CESAs in vivo. Additionally, we show that the stability of all three CESAs within the PCW CSC is altered by mutations in individual CESAs, elevated temperature, and light conditions. Together, these results suggest that CESA proteins are very stable in vivo, but that their lifetimes can be modulated by intrinsic and environmental cues.

  18. A truncated receptor-binding domain of MERS-CoV spike protein potently inhibits MERS-CoV infection and induces strong neutralizing antibody responses: implication for developing therapeutics and vaccines.

    Directory of Open Access Journals (Sweden)

    Lanying Du

    Full Text Available An emerging respiratory infectious disease with high mortality, Middle East respiratory syndrome (MERS, is caused by a novel coronavirus (MERS-CoV. It was first reported in 2012 in Saudi Arabia and has now spread to eight countries. Development of effective therapeutics and vaccines is crucial to save lives and halt the spread of MERS-CoV. Here, we show that a recombinant protein containing a 212-amino acid fragment (residues 377-588 in the truncated receptor-binding domain (RBD: residues 367-606 of MERS-CoV spike (S protein fused with human IgG Fc fragment (S377-588-Fc is highly expressed in the culture supernatant of transfected 293T cells. The purified S377-588-Fc protein efficiently binds to dipeptidyl peptidase 4 (DPP4, the receptor of MERS-CoV, and potently inhibited MERS-CoV infection, suggesting its potential to be further developed as a therapeutic modality for treating MERS-CoV infection and saving the patients' lives. The recombinant S377-588-Fc is able to induce in the vaccinated mice strong MERS-CoV S-specific antibodies, which blocks the binding of RBD to DPP4 receptor and effectively neutralizes MERS-CoV infection. These findings indicate that this truncated RBD protein shows promise for further development as an effective and safe vaccine for the prevention of MERS-CoV infection.

  19. Cellulose nanocrystal properties and their applications

    Directory of Open Access Journals (Sweden)

    mahdi jonoobi

    2015-05-01

    Full Text Available The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance, their renewability, high strength and stiffness, being eco-friendly, and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals from various sources. The rod-like cellulose nanocrystals (CNC can be isolated from sources like wood, plant fibers, agriculture and industrial bio residues, tunicates, and bacterial cellulose using acid hydrolysis process. Following this, the paper focused on characterization methods, materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.

  20. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, Sara; Li, Z.; Behzad, Ali Reza; Peinemann, Klaus-Viktor; Nunes, Suzana Pereira

    2015-01-01

    and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions

  1. Cellulose nanocrystal submonolayers by spin coating

    NARCIS (Netherlands)

    Kontturi, E.J.; Johansson, L.S.; Kontturi, K.S.; Ahonen, P.; Thune, P.C.; Laine, J.

    2007-01-01

    Dilute concentrations of cellulose nanocrystal solutions were spin coated onto different substrates to investigate the effect of the substrate on the nanocrystal submonolayers. Three substrates were probed: silica, titania, and amorphous cellulose. According to atomic force microscopy (AFM) images,

  2. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  3. Characterization of Cellulose Synthesis in Plant Cells

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  4. A Molecular Description of Cellulose Biosynthesis

    Science.gov (United States)

    McNamara, Joshua T.; Morgan, Jacob L.W.; Zimmer, Jochen

    2016-01-01

    Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed. PMID:26034894

  5. Raman spectroscopy in the analysis of cellulose nanomaterials

    Science.gov (United States)

    Umesh P. Agarwal

    2017-01-01

    Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when...

  6. Radiation modification of cellulose pulps. Preparation of cellulose derivatives

    International Nuclear Information System (INIS)

    Iller, E.; Zimek, Z.; Stupinska, H.; Mikolajczyk, W; Starostka, P.

    2005-01-01

    One of the most common methods of cellulose pulp modification (activation) applied in the production process of cellulose derivatives is the treatment of the pulp with NaOH solutions leading to the formation of alkalicellulose. The product then undergoes a prolonged process of maturation by its storage under specific conditions. The goal of the process is lowering of the molecular weight of cellulose down to the level resulting from various technological requirements. The process is time-consuming and costly; besides, it requires usage of large-capacity technological vessels and produces considerable amounts of liquid waste. Therefore, many attempts have been made to limit or altogether eliminate the highly disadvantageous stage of cellulose treatment with lye. One of the alternatives proposed so far is the radiation treatment of the cellulose pulp. In the pulp exposed to an electron beam, the bonds between molecules of D-antihydroglucopiranoses loosen and the local crystalline lattice becomes destroyed. This facilitates the access of chemical reagents to the inner structure of the cellulose and, in consequence, eliminates the need for the prolonged maturation of alkalicellulose, thus reducing the consumption of chemicals by the whole process. Research aimed at the application of radiation treatment of cellulose pulp for the production of cellulose derivatives has been conducted by a number of scientific institutions including the Institute of Nuclear Chemistry and Technology, Institute of Biopolymers and Chemical Fibres, and Pulp and Paper Research Institute. For the investigations and assessment of the molecular, hypermolecular, morphologic properties and the chemical reactivity, cellulose pulps used for chemical processing, namely Alicell, Borregaard and Ketchikan, as well as paper pulps made from pine and birch wood were selected. The selected cellulose pulps were exposed to an electron beam with an energy of 10 MeV generated in a linear electron accelerator

  7. Enzymatic hydrolysis of cellulosic materials by Sclerotium rolfsii culture filtrate for sugar production

    Energy Technology Data Exchange (ETDEWEB)

    Shewale, J G; Sadana, J C

    1979-06-01

    The hydrolysis of purified celluloses (cotton, Avicel, Cellulose-123, Solka Floc SW40) and cellulosic wastes (rice straw, sugarcane bagasse, wood powders, paper factory effluents) by Sclerotium rolfsii CPC 142 culture filtrate was studied. Factors which effect saccharification such as pH, temperature, enzyme concentration, substrate concentration, produce inhibition, adsorption, and inactivation of enzyme and particle size were studied. Virtually no inhibition (less than 3%) of cellulose hydrolysis by the culture filtrate was observed by cellobiose and glucose up to 100 mg/mL. Filter paper degrading enzyme(s) (but neither carboxymethylcellulase nor beta-glucosidase) was adsorbed on cellulose. The n value in the S. rolfsii system was calculated to be 0.32 for Avicel P.H. 101 and 0.53 for alkali-treated (AT) rice straw indicating penetration of cellulase into AT rice straw. In batch experiments at 10% substrate level, solutions containing 6 to 7%, 3.8 to 4.7%, 4.0 to 5.1%, and 4.2 to 4.9% reducing sugars were produced in 24 to 48 from AT rice straw. AT bagasse, alkali - peracetic acid treated mesta wood and paper factory sedimented sludge effluent, respectively. The main constituent in the hydrolysate from cellulose was glucose with little or no cellobiose, probably due to the high cellobiase content in the culture filtrate.

  8. Properties of microcrystalline cellulose obtained from coconut ...

    African Journals Online (AJOL)

    The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose. Keywords: Coconut fruit fibre, microcrystalline cellulose, powder properties. Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: ...

  9. Method of producing thin cellulose nitrate film

    International Nuclear Information System (INIS)

    Lupica, S.B.

    1975-01-01

    An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent

  10. Bioengineering cellulose-hemicellulose networks in plants

    NARCIS (Netherlands)

    Obembe, O.

    2006-01-01

    The interactions between cellulose and hemicellulose in the cell walls are important in the industrial application of the cellulose (natural) fibres. We strive to modify these interactions (i) by interfering with cellulose biosynthesis and (ii) by direct interference of the

  11. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  12. 21 CFR 172.870 - Hydroxypropyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydroxypropyl cellulose. 172.870 Section 172.870... CONSUMPTION Multipurpose Additives § 172.870 Hydroxypropyl cellulose. The food additive hydroxypropyl cellulose may be safely used in food, except standardized foods that do not provide for such use, in...

  13. Cellulose nanomaterials review: structure, properties and nanocomposites

    Science.gov (United States)

    Robert J. Moon; Ashlie Martini; John Nairn; John Simonsen; Jeff Youngblood

    2011-01-01

    This critical review provides a processing-structure-property perspective on recent advances in cellulose nanoparticles and composites produced from them. It summarizes cellulose nanoparticles in terms of particle morphology, crystal structure, and properties. Also described are the self-assembly and rheological properties of cellulose nanoparticle suspensions. The...

  14. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Science.gov (United States)

    Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

    2014-01-01

    Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. PMID:25000264

  15. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  16. Degradation of cellulose in the presence of ash; Nedbrytningsmoenster foer cellulosa i naervaro av aska

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, Karin; Berg, Magnus [AaF-Energi och Miljoe AB, Stockholm (Sweden); Svensson, Malin; Ecke, Holger [Luleaa Univ. of Tech. (Sweden)

    2003-04-01

    This project evaluates the risks and possibilities that come up in mixtures of ash and cellulose. The focus is on alkaline degradation of cellulose and the impact on metal leaching. The literature survey shows that a combination of ash and cellulose affects both the mobility of metals and the degradation of cellulose in many ways. A combination of ash and cellulose could have positive effects on the degradation of cellulose since ash makes the pH rise in the material. Normally the pH decreases in a waste deposit with time, which results in a reduced biological degradation of the cellulose since the methanogenic organisms are sensitive for low pH values. However, even if the pH increases when cellulose is mixed with ash the methanogenic organisms could be inhibit by toxic metals. The highest degradation rate for cellulose is at natural pH values because of an effective biological degradation. If alkaline conditions appear when cellulose is mixed with ash or in contact with the leaching water the cellulose is going to be degraded by a slower process: non-biological degradation (peeling-off reactions). The main degradation product from peeling-off reactions of cellulose is isosaccharinic acid (ISA). ISA forms complex with metals, which results in increased mobilization and leaching of metals. From biological degradation the degradation products are mainly CO{sub 2} and H{sub 2}O under aerobic conditions and CO{sub 2} and CH{sub 4} under anaerobic conditions. In combinations of ash and cellulose is it possible that the formed carbon dioxide cause carbonation and fixation of metals in the ash. As mentioned, ash could result in an increment of the pH value in cellulose materials, but if the starting point is pure ash a mixture with cellulose could make the pH value decrease, in extreme cases down to 4-5, because of biological degradation. Therefore it is possible that the metal mobilization in ash will increase if the ash is mixed with cellulose. Increased leaching of

  17. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    Science.gov (United States)

    Somerville, Chris R [Portola Valley, CA; Scheible, Wolf [Golm, DE

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  18. Influence of cellulose ether particle size on water retention of freshly-mixed mortars

    OpenAIRE

    Patural , Laetitia; Govin , Alexandre; Grosseau , Philippe; Ruot , Bertrand; Deves , Olivier

    2009-01-01

    International audience; Cellulose ethers are polymers frequently introduced into mortar formulations in order to improve water retention capacity and workability of the freshly-mixed materials. Physico-chemical parameters of these admixtures (molecular weight, granulometry, substitution degrees, etc) seem to have a strong influence on mortar water retention capacity. In this paper, the influence of cellulose ether particle size was studied. Two behaviors were highlighted regarding the particl...

  19. Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells

    Directory of Open Access Journals (Sweden)

    Chukwuemeka P. Azubuike

    2012-09-01

    Full Text Available α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow properties were investigated. α–Cellulose (GCN was extracted from groundnut shell (an agricultural waste product using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN. The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA, using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α-cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.

  20. Inhibition of lignin-derived phenolic compounds to cellulase.

    Science.gov (United States)

    Qin, Lei; Li, Wen-Chao; Liu, Li; Zhu, Jia-Qing; Li, Xia; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-01-01

    Lignin-derived phenolic compounds are universal in the hydrolysate of pretreated lignocellulosic biomass. The phenolics reduce the efficiency of enzymatic hydrolysis and increase the cost of ethanol production. We investigated inhibition of phenolics on cellulase during enzymatic hydrolysis using vanillin as one of the typical lignin-derived phenolics and Avicel as cellulose substrate. As vanillin concentration increased from 0 to 10 mg/mL, cellulose conversion after 72-h enzymatic hydrolysis decreased from 53 to 26 %. Enzyme deactivation and precipitation were detected with the vanillin addition. The enzyme concentration and activity consecutively decreased during hydrolysis, but the inhibition degree, expressed as the ratio of the cellulose conversion without vanillin to the conversion with vanillin (A 0 /A), was almost independent on hydrolysis time. Inhibition can be mitigated by increasing cellulose loading or cellulase concentration. The inhibition degree showed linear relationship with the vanillin concentration and exponential relationship with the cellulose loading and the cellulase concentration. The addition of calcium chloride, BSA, and Tween 80 did not release the inhibition of vanillin significantly. pH and temperature for hydrolysis also showed no significant impact on inhibition degree. The presence of hydroxyl group, carbonyl group, and methoxy group in phenolics affected the inhibition degree. Besides phenolics concentration, other factors such as cellulose loading, enzyme concentration, and phenolic structure also affect the inhibition of cellulose conversion. Lignin-blocking agents have little effect on the inhibition effect of soluble phenolics, indicating that the inhibition mechanism of phenolics to enzyme is likely different from insoluble lignin. The inhibition of soluble phenolics can hardly be entirely removed by increasing enzyme concentration or adding blocking proteins due to the dispersity and multiple binding sites of phenolics

  1. Advancing cellulose-based nanotechnology

    Science.gov (United States)

    Theodore H. Wegner; Philip E. Jones

    2006-01-01

    Nanotechnology has applications across most economic sectors and allows the development of new enabling science with broad commercial potential. Cellulose and lignocellulose have great potential as nanomaterials because they are abundant, renewable, have a nanofibrillar structure, can be made multifunctional, and self-assemble into well-defined architectures. To...

  2. Ignition inhibitors for cellulosic materials

    International Nuclear Information System (INIS)

    Alvares, N.J.

    1976-01-01

    By exposing samples to various irradiance levels from a calibrated thermal radiation source, the ignition responses of blackened alpha-cellulose and cotton cloth with and without fire-retardant additives were compared. Samples treated with retardant compounds which showed the most promise were then isothermally pyrolyzed in air for comparisons between the pyrolysis rates. Alpha-cellulose samples containing a mixture of boric acid, borax, and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal cm -2 s-1 (16.7 W/cm 2 ). At higher irradiances the specimens ignited, but flaming lasted only until the flammable gases were depleted. Cotton cloth containing a polymeric retardant with the designation THPC + MM was found to be ignition-resistant to all irradiances below 7.0 cal cm -2 s -1 (29.3 W/cm 2 ). Comparison of the pyrolysis rates of the retardant-treated alpha-cellulose and the retardant-treated cotton showed that the retardant mechanism is qualitatively the same. Similar ignition-response measurements were also made with specimens exposed to ionizing radiation. It was observed that gamma radiation results in ignition retardance of cellulose, while irradiation by neutrons does not

  3. Polyvinyl alcohol–cellulose composite

    Indian Academy of Sciences (India)

    We have made an attempt to prepare taste sensor material by using functionalized polymer without any lipid. PVA–cellulose composite has been modified to use as the sensor material. The research work covers polymer membrane preparation, morphology study and structural characterization of the membrane and study of ...

  4. Irradiation effects in wood and cellulose

    International Nuclear Information System (INIS)

    McLaren, K.G.

    1976-01-01

    For cellulosic materials the predominant effect of high energy radiation is depolymerisation and degradation by chain scission, although there is some evidence that crosslinking or cellulose stabilisation can occur under certain conditions. When the cellulose is in the form of a natural product such as wood, where it is intimately associated with other polysaccharides, lignins, resins and gums, the effects of radiation can be significantly modified. Examination of cellulose produced by chemical pulping treatment of wood which had been previously given small doses of radiation, showed significant differences in the extent of cellulose depolymerisation with different wood species. The relevance of this work to the paper pulp industry will also be discussed. (author)

  5. Cellulose nanocrystals reinforced foamed nitrile rubber nanocomposites.

    Science.gov (United States)

    Chen, Yukun; Zhang, Yuanbing; Xu, Chuanhui; Cao, Xiaodong

    2015-10-05

    Research on foamed nitrile rubber (NBR)/cellulose nanocrystals (CNs) nanocomposites is rarely found in the literatures. In this paper, CNs suspension and NBR latex was mixed to prepared the foamed NBR/CNs nanocomposites. We found that the CNs mainly located in the cell walls, effectively reinforcing the foamed NBR. The strong interaction between the CNs and NBR matrix restricted the mobility of NBR chains surrounding the CNs, hence increasing the crosslink density of the NBR matrix. CNs exhibited excellent reinforcement on the foamed NBR: a remarkable increase nearly 76% in the tensile strength of the foamed nanocomposites was achieved with a load of only 15 phr CNs. Enhanced mechanical properties make the foamed NBR/CNs nanocomposites a promising damping material for industrial applications with a potential to reduce the petroleum consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Adhesion of cellulose fibers in paper

    International Nuclear Information System (INIS)

    Persson, Bo N J; Ganser, Christian; Schmied, Franz; Teichert, Christian; Schennach, Robert; Gilli, Eduard; Hirn, Ulrich

    2013-01-01

    The surface topography of paper fibers is studied using atomic force microscopy (AFM), and thus the surface roughness power spectrum is obtained. Using AFM we have performed indentation experiments and measured the effective elastic modulus and the penetration hardness as a function of humidity. The influence of water capillary adhesion on the fiberfiber binding strength is studied. Cellulose fibers can absorb a significant amount of water, resulting in swelling and a strong reduction in the elastic modulus and the penetration hardness. This will lead to closer contact between the fibers during the drying process (the capillary bridges pull the fibers into closer contact without storing up a lot of elastic energy at the contacting interface). In order for the contact to remain good in the dry state, plastic flow must occur (in the wet state) so that the dry surface profiles conform to each other (forming a key-and-lock type of contact).

  7. Adhesion of cellulose fibers in paper.

    Science.gov (United States)

    Persson, Bo N J; Ganser, Christian; Schmied, Franz; Teichert, Christian; Schennach, Robert; Gilli, Eduard; Hirn, Ulrich

    2013-01-30

    The surface topography of paper fibers is studied using atomic force microscopy (AFM), and thus the surface roughness power spectrum is obtained. Using AFM we have performed indentation experiments and measured the effective elastic modulus and the penetration hardness as a function of humidity. The influence of water capillary adhesion on the fiber-fiber binding strength is studied. Cellulose fibers can absorb a significant amount of water, resulting in swelling and a strong reduction in the elastic modulus and the penetration hardness. This will lead to closer contact between the fibers during the drying process (the capillary bridges pull the fibers into closer contact without storing up a lot of elastic energy at the contacting interface). In order for the contact to remain good in the dry state, plastic flow must occur (in the wet state) so that the dry surface profiles conform to each other (forming a key-and-lock type of contact).

  8. Lignin depletion enhances the digestibility of cellulose in cultured xylem cells.

    Directory of Open Access Journals (Sweden)

    Catherine I Lacayo

    Full Text Available Plant lignocellulose constitutes an abundant and sustainable source of polysaccharides that can be converted into biofuels. However, the enzymatic digestion of native plant cell walls is inefficient, presenting a considerable barrier to cost-effective biofuel production. In addition to the insolubility of cellulose and hemicellulose, the tight association of lignin with these polysaccharides intensifies the problem of cell wall recalcitrance. To determine the extent to which lignin influences the enzymatic digestion of cellulose, specifically in secondary walls that contain the majority of cellulose and lignin in plants, we used a model system consisting of cultured xylem cells from Zinniaelegans. Rather than using purified cell wall substrates or plant tissue, we have applied this system to study cell wall degradation because it predominantly consists of homogeneous populations of single cells exhibiting large deposits of lignocellulose. We depleted lignin in these cells by treating with an oxidative chemical or by inhibiting lignin biosynthesis, and then examined the resulting cellulose digestibility and accessibility using a fluorescent cellulose-binding probe. Following cellulase digestion, we measured a significant decrease in relative cellulose content in lignin-depleted cells, whereas cells with intact lignin remained essentially unaltered. We also observed a significant increase in probe binding after lignin depletion, indicating that decreased lignin levels improve cellulose accessibility. These results indicate that lignin depletion considerably enhances the digestibility of cellulose in the cell wall by increasing the susceptibility of cellulose to enzymatic attack. Although other wall components are likely to contribute, our quantitative study exploits cultured Zinnia xylem cells to demonstrate the dominant influence of lignin on the enzymatic digestion of the cell wall. This system is simple enough for quantitative image analysis

  9. Structure and engineering of celluloses.

    Science.gov (United States)

    Pérez, Serge; Samain, Daniel

    2010-01-01

    This chapter collates the developments and conclusions of many of the extensive studies that have been conducted on cellulose, with particular emphasis on the structural and morphological features while not ignoring the most recent results derived from the elucidation of unique biosynthetic pathways. The presentation of structural and morphological data gathered together in this chapter follows the historical development of our knowledge of the different structural levels of cellulose and its various organizational levels. These levels concern features such as chain conformation, chain polarity, chain association, crystal polarity, and microfibril structure and organization. This chapter provides some historical landmarks related to the evolution of concepts in the field of biopolymer science, which parallel the developments of novel methods for characterization of complex macromolecular structures. The elucidation of the different structural levels of organization opens the way to relating structure to function and properties. The chemical and biochemical methods that have been developed to dissolve and further modify cellulose chains are briefly covered. Particular emphasis is given to the facets of topochemistry and topoenzymology where the morphological features play a key role in determining unique physicochemical properties. A final chapter addresses what might be considered tomorrow's goal in amplifying the economic importance of cellulose in the context of sustainable development. Selected examples illustrate the types of result that can be obtained when cellulose fibers are no longer viewed as inert substrates, and when the polyhydroxyl nature of their surfaces, as well as their entire structural complexity, are taken into account. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan; Meyer, Anne S.; Mikkelsen, Jørn Dalgaard

    2013-01-01

    Product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. The optimal reaction conditions for two Emericella (Aspergillus) nidulans-derived cellobiohydrolases I and II produced in Pichia pastoris were identified as CBHI: 52 °C, pH 4.5–6.5, and CBHII: 46 °C, pH 4.......8. The optimum in a mixture of the two was 50 °C, pH 4.9. An almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kDa cut-off): The conversion of cotton cellulose after 72 h was ~19 % by weight, whereas the conversion...

  11. Cellulose Nanomaterials in Water Treatment Technologies

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles François; Wiesner, Mark R.

    2015-01-01

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials’ potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials’ beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization. PMID:25837659

  12. Cellulose nanomaterials in water treatment technologies.

    Science.gov (United States)

    Carpenter, Alexis Wells; de Lannoy, Charles-François; Wiesner, Mark R

    2015-05-05

    Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

  13. Polymorphy in native cellulose: recent developments

    International Nuclear Information System (INIS)

    Atalla, R.H.

    1984-01-01

    In a number of earlier studies, the authors developed a model of cellulose structure based on the existence of two stable, linearly ordered conformations of the cellulose chain that are dominant in celluloses I and II, respectively. The model rests on extensive Raman spectral observations together with conformational considerations and solid-state 13 C-NMR studies. More recently, they have proposed, on the basis of high resolution solid-state 13 C-NMR observations, that native celluloses are composites of two distinct crystalline forms that coexist in different proportions in all native celluloses. In the present work, they examine the Raman spectra of the native celluloses, and reconcile their view of conformational differences with the new level of crystalline polymorphy of native celluloses revealed in the solid-state 13 C-NMR investigations

  14. Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp.

    Science.gov (United States)

    Hutterer, Christian; Kliba, Gerhard; Punz, Manuel; Fackler, Karin; Potthast, Antje

    2017-07-01

    The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase. The latter help to adjust cellulose chain lengths for certain dissolving pulp grades while reducing the demand for ozone in subsequent TCF bleaching. Experiments applying different commercially available enzyme preparations revealed the dependency of xylanase performance on the residual xylan content in pulps being stimulated by additional cellulase usage. The action of the latter strongly depends on the cellulose allomorphy confirming the impact of the pulp morphology. Hence, the combined application of both types of enzymes offers a high potential for upgrading pulps in order to produce a pure and high-value cellulose product. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Preparation, Characterization, and Cationic Functionalization of Cellulose-Based Aerogels for Wastewater Clarification

    Directory of Open Access Journals (Sweden)

    Yang Hu

    2016-01-01

    Full Text Available Aerogels are a series of materials with porous structure and light weight which can be applied to many industrial divisions as insulators, sensors, absorbents, and cushions. In this study, cellulose-based aerogels (aerocelluloses were prepared from cellulosic material (microcrystalline cellulose in sodium hydroxide/water solvent system followed by supercritical drying operation. The average specific surface area of aerocelluloses was 124 m2/g. The nitrogen gas (N2 adsorption/desorption isotherms revealed type H1 hysteresis loops for aerocelluloses, suggesting that aerocelluloses may possess a porous structure with cylindrically shaped pores open on both ends. FTIR and XRD analyses showed that the crystallinity of aerocelluloses was significantly decreased as compared to microcrystalline cellulose and that aerocelluloses exhibited a crystalline structure of cellulose II as compared to microcrystalline cellulose (cellulose I. To perform cationic functionalization, a cationic agent, (3-chloro-2-hydroxypropyl trimethylammonium chloride, was used to introduce positively charged sites on aerocelluloses. The cationized aerocelluloses exhibited a strong ability to remove anionic dyes from wastewater. Highly porous and low cost aerocelluloses prepared in this study would be also promising as a fast absorbent for environmental pollutants.

  16. Removal of uranium (VI) from aqueous systems by nanoscale zero-valent iron particles suspended in carboxy-methyl cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, Ioana-Carmen, E-mail: ioana.popescu@icpmrr.ro [R and D National Institute for Metals and Radioactive Resources – ICPMRR Bucharest B-dul Carol I No. 70, Sector 2, 202917 Bucharest (Romania); Filip, Petru [C. D. Nenitescu Institute of Organic Chemistry, Splaiul Independentei 202B, Sector 6, 71141 Bucharest (Romania); Humelnicu, Doina, E-mail: doinah@uaic.ro [Al.I. Cuza University of Iasi, The Faculty of Chemistry, Bd. Carol-I No. 11, Iasi 700506 (Romania); Humelnicu, Ionel [Al.I. Cuza University of Iasi, The Faculty of Chemistry, Bd. Carol-I No. 11, Iasi 700506 (Romania); Scott, Thomas Bligh; Crane, Richard Andrew [Interface Analysis Centre, University of Bristol, 121 St. Michael’s Hill, Bristol BS2 8BS (United Kingdom)

    2013-11-15

    Carboxy-methyl-cellulose (CMC), a common “delivery vehicle” for the subsurface deployment of iron nanoparticles (INP) has been tested in the current work for the removal of aqueous uranium from synthetic water samples. A comparison of the removal of aqueous uranium from solutions using carboxy-methyl-cellulose with and without iron nanoparticles (CMC–INP and CMC, respectively) was tested over a 48 h reaction period. Analysis of liquid samples using spectrophotometry determined a maximum sorption capacity of uranium, Q{sub max}, of 185.18 mg/g and 322.58 mg/g for CMC and CMC–INP respectively, providing strong evidence of an independent aqueous uranium removal ability exhibited by CMC. The results point out that CMC provides an additional capacity for aqueous uranium removal. Further tests are required to determine whether similar behaviour will be observed for other aqueous contaminant species and if the presence of CMC within a INP slurry inhibits or aids the reactivity, reductive capacity and affinity of INP for aqueous contaminant removal.

  17. Cellulose Triacetate Synthesis from Cellulosic Wastes by Heterogeneous Reactions

    Directory of Open Access Journals (Sweden)

    Sherif Shawki Z. Hindi

    2015-06-01

    Full Text Available Cellulosic fibers from cotton fibers (CF, recycled writing papers (RWP, recycled newspapers (RN, and macerated woody fibers of Leucaena leucocephala (MWFL were acetylated by heterogeneous reactions with glacial acetic acid, concentrated H2SO4, and acetic anhydride. The resultant cellulose triacetate (CTA was characterized for yield and solubility as well as by using 1H-NMR spectroscopy and SEM. The acetylated product (AP yields for CF, RWP, RN, and MWFL were 112, 94, 84, and 73%, respectively. After isolation of pure CTA from the AP, the CTA yields were 87, 80, 68, and 54%. The solubility test for the CTA’s showed a clear solubility in chloroform, as well as mixture of chloroform and methanol (9:1v/v and vice versa for acetone. The degree of substitution (DS values for the CTA’s produced were nearly identical and confirmed the presence of CTA. In addition, the pore diameter of the CTA skeleton ranged from 0.072 to 0.239 µm for RWP and RN, and within the dimension scale of the CTA pinholes confirm the synthesis of CTA. Accordingly, pouring of the AP liquor at 25 °C in distilled water at the end of the acetylation and filtration did not hydrolyze the CTA to cellulose diacetate.

  18. Cellulose Degradation at Alkaline Conditions: Long-Term Experiments at Elevated Temperatures

    International Nuclear Information System (INIS)

    Glaus, M.A.; Van Loon, L.R.

    2004-04-01

    temperatures tested here. It may be hypothesised that the alkaline hydrolysis has even not been observed in the experiments. However, if this is true, cellulose degradation proceeded via another unknown type of reaction. Mass balances for carbon show that the large majority of reaction products found in solution can be explained by formation of isosaccharinic acids and other low-molecular weight carboxylic acids. With respect to long-term predictions for cellulose degradation at room temperature it can be concluded that the kinetic parameters for alkaline hydrolysis as proposed in the work of PAVASARS (Linkoping Studies in Arts and Science, 196, Linkoping University, Sweden, 1999) are too large and that complete cellulose degradation at these temperatures occurs only within time scales larger than hundreds of years. However, it is not possible from the experimental evidences, to corroborate the validity of a linear extrapolation (Arrhenius equation) of the reaction rates measured at temperatures between 140 and 190 o C to room temperature, from which it was previously concluded that complete cellulose degradation would take time spans of the order of millions of years. An interesting observation in the present experiments is the chemical instability of aisosaccharinic acid at 90 o C, which has been hypothetically interpreted as a fragmentation induced by the sorption of α-isosaccharinic acid on Ca(OH) 2 . Carbon mass balances show that α-isosaccharinic acid is thereby transformed to other lowmolecular weight carboxylic acids. Such a reaction would be an interesting long-term perspective for performance assessment of the disposal of cellulose-containing radioactive waste, in that it may reduce the concentration of organic compounds strongly complexing radionuclides. (author)

  19. Cellulose Degradation at Alkaline Conditions: Long-Term Experiments at Elevated Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Glaus, M.A.; Van Loon, L.R

    2004-04-01

    hydrolysis at the temperatures tested here. It may be hypothesised that the alkaline hydrolysis has even not been observed in the experiments. However, if this is true, cellulose degradation proceeded via another unknown type of reaction. Mass balances for carbon show that the large majority of reaction products found in solution can be explained by formation of isosaccharinic acids and other low-molecular weight carboxylic acids. With respect to long-term predictions for cellulose degradation at room temperature it can be concluded that the kinetic parameters for alkaline hydrolysis as proposed in the work of PAVASARS (Linkoping Studies in Arts and Science, 196, Linkoping University, Sweden, 1999) are too large and that complete cellulose degradation at these temperatures occurs only within time scales larger than hundreds of years. However, it is not possible from the experimental evidences, to corroborate the validity of a linear extrapolation (Arrhenius equation) of the reaction rates measured at temperatures between 140 and 190{sup o}C to room temperature, from which it was previously concluded that complete cellulose degradation would take time spans of the order of millions of years. An interesting observation in the present experiments is the chemical instability of aisosaccharinic acid at 90{sup o}C, which has been hypothetically interpreted as a fragmentation induced by the sorption of {alpha}-isosaccharinic acid on Ca(OH){sub 2}. Carbon mass balances show that {alpha}-isosaccharinic acid is thereby transformed to other lowmolecular weight carboxylic acids. Such a reaction would be an interesting long-term perspective for performance assessment of the disposal of cellulose-containing radioactive waste, in that it may reduce the concentration of organic compounds strongly complexing radionuclides. (author)

  20. CELLULOSE DEGRADATION BY OXIDATIVE ENZYMES

    Directory of Open Access Journals (Sweden)

    Maria Dimarogona

    2012-09-01

    Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

  1. γ radiolysis of cellulose acetate

    International Nuclear Information System (INIS)

    Ali, S.M.; Clay, P.G.

    1979-01-01

    The major degradative process in γ-irradiated cellulose acetate is chain scission. For the dry powder the G/sub s/ value (number of scissions per 100 eV of energy absorbed) was found to be 7.1. The water-swollen material was found to degrade at the higher rate of G/sub s/ = 9.45. Additions of ethanol and methanol to the water brought about reductions in G/sub s/, whereas dissolved nitrous oxide produced an increase in G/sub s/. The useful life of cellulose acetate reverse osmosis membranes exposed to γ radiation was estimated by observations of the water permeation rate during irradiation. Membrane breakdown occurred at 15 Mrad in pure water, but the dose to breakdown was extended to 83 Mrad in the presence of 4% methanol. 3 figures, 1 table

  2. Polyimide Cellulose Nanocrystal Composite Aerogels

    Science.gov (United States)

    Nguyen, Baochau N.; Meador, Mary Ann; Rowan, Stuart; Cudjoe, Elvis; Sandberg, Anna

    2014-01-01

    Polyimide (PI) aerogels are highly porous solids having low density, high porosity and low thermal conductivity with good mechanical properties. They are ideal for various applications including use in antenna and insulation such as inflatable decelerators used in entry, decent and landing operations. Recently, attention has been focused on stimuli responsive materials such as cellulose nano crystals (CNCs). CNCs are environmentally friendly, bio-renewable, commonly found in plants and the dermis of sea tunicates, and potentially low cost. This study is to examine the effects of CNC on the polyimide aerogels. The CNC used in this project are extracted from mantle of a sea creature called tunicates. A series of polyimide cellulose nanocrystal composite aerogels has been fabricated having 0-13 wt of CNC. Results will be discussed.

  3. Non-cellulosic polysaccharides from cotton fibre are differently impacted by textile processing

    DEFF Research Database (Denmark)

    Runavot, Jean-Luc; Guo, Xiaoyuan; Willats, William George Tycho

    2014-01-01

    -cellulosic cotton fibre polysaccharides during different steps of cotton textile processing using GC-MS, HPLC and comprehensive microarray polymer profiling to obtain monosaccharide and polysaccharide amounts and linkage compositions. Additionally, in situ detection was used to obtain information on polysaccharide......Cotton fibre is mainly composed of cellulose, although non-cellulosic polysaccharides play key roles during fibre development and are still present in the harvested fibre. This study aimed at determining the fate of non-cellulosic polysaccharides during cotton textile processing. We analyzed non...... localization and accessibility. We show that pectic and hemicellulosic polysaccharide levels decrease during cotton textile processing and that some processing steps have more impact than others. Pectins and arabinose-containing polysaccharides are strongly impacted by the chemical treatments, with most being...

  4. Process Intensification for Cellulosic Biorefineries.

    Science.gov (United States)

    Sadula, Sunitha; Athaley, Abhay; Zheng, Weiqing; Ierapetritou, Marianthi; Saha, Basudeb

    2017-06-22

    Utilization of renewable carbon source, especially non-food biomass is critical to address the climate change and future energy challenge. Current chemical and enzymatic processes for producing cellulosic sugars are multistep, and energy- and water-intensive. Techno-economic analysis (TEA) suggests that upstream lignocellulose processing is a major hurdle to the economic viability of the cellulosic biorefineries. Process intensification, which integrates processes and uses less water and energy, has the potential to overcome the aforementioned challenges. Here, we demonstrate a one-pot depolymerization and saccharification process of woody biomass, energy crops, and agricultural residues to produce soluble sugars with high yields. Lignin is separated as a solid for selective upgrading. Further integration of our upstream process with a reactive extraction step makes energy-efficient separation of sugars in the form of furans. TEA reveals that the process efficiency and integration enable, for the first time, economic production of feed streams that could profoundly improve process economics for downstream cellulosic bioproducts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Utilization of agricultural cellulose wastes

    Energy Technology Data Exchange (ETDEWEB)

    Valkanas, G N; Economidis, D G; Koukios, E G; Valkanas, C G

    1977-05-05

    Wastes, example, straw, are prehydrolyzed to convert pentosanes, starches, and hemicelluloses to monosaccharides; the remaining pulp is 50% cellulose. Thus, dry wheat straw 0.8 kg was treated with 10 L of 0.3% aqueous HCl at 5-5.5 atm and 145/sup 0/ and a space velocity of 0.55 L/min, washed with dry steam, followed by water at 120 to 130/sup 0/, and more dry steam, and compressed at 25 kg/cm/sup 2/ to yield a product containing 45 to 50 wt % water. The sugar solution obtained (1394 L) contained 1.34 wt % reducing sugars, a straw hydrolysis of 23 wt %, and comprised xylose 74.3, mannose 5.2, arabinose 11.8, glucose 5.9, galactose 2.9%, and furfural 0.16 g/L. The cellulose residue had a dry weight of 0.545 kg. a yield of 68.2 wt % and contained cellulose 53.1, hemicelluloses 12.6%, lignin 22.1, ash and extractables 12.2%. The degree of polymerization was 805 glucose units.

  6. PRESENTED AT NC SOCIETY OF TOXICOLOGY MEETING IN RESEARCH TRIANGLE PARK, NC ON 2/16/2006: PERIPUBERTAL PROCHLORAZ EXPOSURE STRONGLY INHIBITS TESTOSTERONE PRODUCTION, BUT HAS WEAK EFFECTS ON PUBERTY

    Science.gov (United States)

    Prochloraz (PCZ) is an imidazole fungicide that inhibits steroidogenesis and acts as an androgen receptor antagonist. We hypothesized that pubertal exposure to prochloraz would delay preputial separation and development of reproductive organs. Sprague Dawley rats were dosed wit...

  7. Effects of Forest Gaps on Litter Lignin and Cellulose Dynamics Vary Seasonally in an Alpine Forest

    Directory of Open Access Journals (Sweden)

    Han Li

    2016-01-01

    Full Text Available To understand how forest gaps and the associated canopy control litter lignin and cellulose dynamics by redistributing the winter snow coverage and hydrothermal conditions in the growing season, a field litterbag trial was conducted in the alpine Minjiang fir (Abies faxoniana Rehder and E.H. Wilson forest in a transitional area located in the upper reaches of the Yangtze River and the eastern Tibetan Plateau. Over the first year of litter decomposition, the litter exhibited absolute cellulose loss and absolute lignin accumulation except for the red birch litter. The changes in litter cellulose and lignin were significantly affected by the interactions among gap position, period and species. Litter cellulose exhibited a greater loss in the winter with the highest daily loss rate observed during the snow cover period. Both cellulose and lignin exhibited greater changes under the deep snow cover at the gap center in the winter, but the opposite pattern occurred under the closed canopy in the growing season. The results suggest that decreased snowpack seasonality due to winter warming may limit litter cellulose and lignin degradation in alpine forest ecosystems, which could further inhibit litter decomposition. As a result, the ongoing winter warming and gap vanishing would slow soil carbon sequestration from foliar litter in cold biomes.

  8. Cellulose-containing Waste and Bituminized Salts

    International Nuclear Information System (INIS)

    Valcke, E.

    2005-01-01

    In Belgium, Medium-Level radioactive Waste (MLW) would be eventually disposed off in an underground repository in a geological formation such as the Boom Clay, which is studied as a reference host rock formation. MLW contains large quantities of non-radioactive chemicals that are released upon contact with pore water. It could be the case, for instance, for plutonium bearing cellulosic waste - such as paper tissues used to clean alpha glove boxes - issued from nuclear fuel fabrication (Belgonucleaire). At high pH, as in a disposal gallery backfilled with cement, the chemical degradation of cellulose will generate water-soluble products that may form strong complexes with actinides such as Am, Pu, Np, and U. This could lower the sorption of these elements onto the clay minerals, and hence increase their migration through the clay barrier. Another chemical perturbation could occur from the 3000 m 3 of so-called Eurobitum bituminised MLW, with precipitation sludges from the chemical treatment of spent nuclear fuel, and containing about 750 tons of NaNO 3 . The presence of NaNO 3 in this waste will give rise to several processes susceptible to affect the safety of the disposal system. Amongst others, it is necessary to verify that the swelling pressure of bitumen on the gallery wall and the osmotic pressure within the near-field are not too high to induce a fissuration of the host rock, leading to the formation of preferential migration pathways. The major objective of our work is to obtain a broad understanding of the different processes induced by the release of non-radioactive chemicals in the clay formation, to assess the chemical compatibility of different MLW forms with the clay

  9. Biochemistry of cellulose degradation and cellulose utilization for feeds and for protein

    Energy Technology Data Exchange (ETDEWEB)

    Sadara, J C; Lachke, A H; Shewale, J G

    1979-01-01

    A review discussing production of single-cell protein, fuel, and glucose from cellulose decomposition; surface or solid fermentations of single-cell protein; production of cellulases; and the biochemistry of cellulose degradation was presented.

  10. Cellulose-binding domains: tools for innovation in cellulosic fibre production and modification

    NARCIS (Netherlands)

    Quentin, M.G.E.; Valk, van der H.C.P.M.; Dam, van J.E.G.; Jong, de E.

    2003-01-01

    Plant cell walls are composed of cellulose, nature's most abundant macromolecule, and therefore represent a renewable resource of special technical importance. Cellulose degrading enzymes involved in plant cell wall loosening (expansins), or produced by plant pathogenic microorganisms (cellulases),

  11. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara; Akhtar, Faheem Hassan; Ogieglo, Wojciech; Alharbi, Ohoud; Peinemann, Klaus-Viktor

    2018-01-01

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration

  12. Alexa Fluor-labeled Fluorescent Cellulose Nanocrystals for Bioimaging Solid Cellulose in Spatially Structured Microenvironments

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Mo, Kai-For; Shin, Yongsoon; Vasdekis, Andreas; Warner, Marvin G.; Kelly, Ryan T.; Orr, Galya; Hu, Dehong; Dehoff, Karl J.; Brockman, Fred J.; Wilkins, Michael J.

    2015-03-18

    Cellulose nanocrystal materials have been labeled with modern Alexa Fluor dyes in a process that first links the dye to a cyanuric chloride molecule. Subsequent reaction with cellulose nanocrystals provides dyed solid microcrystalline cellulose material that can be used for bioimaging and suitable for deposition in films and spatially structured microenvironments. It is demonstrated with single molecular fluorescence microscopy that these films are subject to hydrolysis by cellulose enzymes.

  13. Cellulose powder from Cladophora sp. algae.

    Science.gov (United States)

    Ek, R; Gustafsson, C; Nutt, A; Iversen, T; Nyström, C

    1998-01-01

    The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (approximately 100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.

  14. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1977-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artificial test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiography by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (Auth.)

  15. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1976-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artifical test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiographs by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (orig.) [de

  16. Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

    Directory of Open Access Journals (Sweden)

    Hernane S. Barud

    2011-01-01

    Full Text Available Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by “in situ” preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and absorption in the UV-Visible (350 nm to 600 nm. Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

  17. Interrelationships between cellulase activity and cellulose particle morphology

    DEFF Research Database (Denmark)

    Olsen, Johan Pelck; Donohoe, Bryon S.; Borch, Kim

    2016-01-01

    It is well documented that the enzymatic hydrolysis of cellulose follows a reaction pattern where an initial phase of relatively high activity is followed by a gradual slow-down over the entire course of the reaction. This phenomenon is not readily explained by conventional factors like substrate...... on this observation we argue that cellulose structure, specifically surface area and roughness, plays a major role in the ubiquitous rate loss observed for cellulases....... depletion, product inhibition or enzyme instability. It has been suggested that the underlying reason for the loss of enzyme activity is connected to the heterogeneous structure of cellulose, but so far attempts to establish quantitative measures of such a correlation remain speculative. Here, we have...... to observe and quantify structural features at μm and nm resolution, respectively. We implemented a semi-automatic image analysis protocol, which allowed us to analyze almost 3000 individual micrographs comprising a total of more than 300,000 particles. From this analysis we estimated the temporal...

  18. Chemo-catalytic valorization of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Palkovits, R. [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie

    2012-07-01

    Cellulose can be utilized as carbon source for the production of novel platform molecules as well as fuel motifs. Promising transformation strategies cover the hydrolytic hydrogenation or hydrogenolysis of cellulose to sugar alcohols, the hydrolysis of cellulose to glucose followed by dehydration to 5-hydroxymethylfurfural or levulinic acid and the further hydrogenation of levulinic acid to {gamma}-valerolactone. Main challenges result from the high degree of functionalization of cellulosic feedstocks. In line, processes are carried out in liquid phase utilizing rather polar solvents and aiming for a tailored defunctionalisation of these oxygen rich compounds. Consequently, such transformations require novel strategies concerning the development of suitable catalysts and appropriate process concepts. (orig.)

  19. Liquid crystalline solutions of cellulose in phosphoric acid for preparing cellulose yarns

    NARCIS (Netherlands)

    Boerstoel, H.

    2006-01-01

    The presen thesis describes a new process for manufacturing high tenacity and high modulus cellulose yarns. A new direct solvent for cellulose has been discovered, leading to liquid crystalline solutions. This new solvent, superphosphoric acid, rapidly dissolves cellulose. These liquid crystalline

  20. Conversion of bagasse cellulose into ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Cuzens, J.E.

    1997-11-19

    The study conducted by Arkenol was designed to test the conversion of feedstocks such as sugar cane bagasse, sorghum, napier grass and rice straw into fermentable sugars, and then ferment these sugars using natural yeasts and genetically engineered Zymomonis mobilis bacteria (ZM). The study did convert various cellulosic feedstocks into fermentable sugars utilizing the patented Arkenol Concentrated Acid Hydrolysis Process and equipment at the Arkenol Technology Center in Orange, California. The sugars produced using this process were in the concentration range of 12--15%, much higher than the sugar concentrations the genetically engineered ZM bacteria had been developed for. As a result, while the ZM bacteria fermented the produced sugars without initial inhibition, the completion of high sugar concentration fermentations was slower and at lower yield than predicted by the National Renewable Energy Laboratory (NREL). Natural yeasts performed as expected by Arkenol, similar to the results obtained over the last four years of testing. Overall, at sugar concentrations in the 10--13% range, yeast produced 850090% theoretical ethanol yields and ZM bacteria produced 82--87% theoretical yields in 96 hour fermentations. Additional commercialization work revealed the ability to centrifugally separate and recycle the ZM bacteria after fermentation, slight additional benefits from mixed culture ZM bacteria fermentations, and successful utilization of defined media for ZM bacteria fermentation nutrients in lieu of natural media.

  1. [Audiometry in the cellulose industry].

    Science.gov (United States)

    Corrao, C R; Milano, L; Pedulla, P; Carlesi, G; Bacaloni, A; Monaco, E

    1993-01-01

    A noise level dosimetry and audiometric testing were conducted in a cellulose factory to determine the hazardous noise level and the prevalence of noise induced hearing loss among the exposed workers. The noise level was recorded up to 90 db (A) in several working areas. 18 workers, potentially exposed to noise injury, evidenced a significant hearing loss. While no evidence of noise injury was recorded in a control group of 100 subjects. This finding suggest a strict relationship between audiometric tests, the noise level recorded in the working place and the working seniority of exposed employers.

  2. Using heavy-ion mutagenesis technology to select cellulose enzyme vitality of mutants of Aspergillium niger

    International Nuclear Information System (INIS)

    Tang Jiahui; Yang Fumin; Wang Shuyang

    2012-01-01

    In order to improve the cellulose ion beam at 20, 40, 60, 80, 100, 120Gy and 140 enzyme vitality of Aspergillus niger (=AS3.316), heavy Gy doses was used for inducing mutation. Higher cellulose enzyme vitality strains were screened through the primary screening and secondary screening. The result showed that 5 mutants T2-1, T3-1, T5-1, T6-3, T6-4 were selected, and T6-4 had the highest cellulose enzyme activity. The activity of filter paper cellulose enzyme, endo-glucanase, exo-glucanase and 13-glucosidase of T6-4 was 61.3, 116.2, 29.9 U/mL and 35.9 U/mL respectively. Compared with the original A. niger (=AS3.316), the cellulose enzyme activity was increased by 3.5, 3.78, 2.76 and 2.52 times in turn. The activity of cellulose enzyme of the rest mutants sorted from strong to the weak were T6-3T5-1T3-1T2-1. The dose at 120 Gy showed the best mutagenesis effect. Mutants had different degree of changes in the genetic stability, but overall, the performance showed relatively stable

  3. Mild and modular surface modification of cellulose via hetero Diels-Alder (HDA) cycloaddition.

    Science.gov (United States)

    Goldmann, Anja S; Tischer, Thomas; Barner, Leonie; Bruns, Michael; Barner-Kowollik, Christopher

    2011-04-11

    A combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and hetero Diels-Alder (HDA) cycloaddition was used to effect, under mild (T ≈ 20 °C), fast, and modular conditions, the grafting of poly(isobornyl acrylate) (M(n) = 9800 g mol(-1), PDI = 1.19) onto a solid cellulose substrate. The active hydroxyl groups expressed on the cellulose fibers were converted to tosylate leaving groups, which were subsequently substituted by a highly reactive cyclopentadienyl functionality (Cp). By employing the reactive Cp-functionality as a diene, thiocarbonyl thio-capped poly(isobornyl acrylate) synthesized via RAFT polymerization (mediated by benzyl pyridine-2-yldithioformiate (BPDF)) was attached to the surface under ambient conditions by an HDA cycloaddition (reaction time: 15 h). The surface-modified cellulose samples were analyzed in-depth by X-ray photoelectron spectroscopy, scanning electron microscopy, elemental analysis, Fourier transform infrared (FT-IR) spectroscopy as well as Fourier transform infrared microscopy employing a focal plane array detector for imaging purposes. The analytical results provide strong evidence that the reaction of suitable dienophiles with Cp-functional cellulose proceeds under mild reaction conditions (T ≈ 20 °C) in an efficient fashion. In particular, the visualization of individual modified cellulose fibers via high-resolution FT-IR microscopy corroborates the homogeneous distribution of the polymer film on the cellulose fibers.

  4. Recombinant rubistatin (r-Rub), an MVD disintegrin, inhibits cell migration and proliferation, and is a strong apoptotic inducer of the human melanoma cell line SK-Mel-28.

    Science.gov (United States)

    Carey, Clayton M; Bueno, Raymund; Gutierrez, Daniel A; Petro, Christopher; Lucena, Sara E; Sanchez, Elda E; Soto, Julio G

    2012-02-01

    Disintegrins are low molecular weight peptides isolated from viper venom. These peptides bind to integrin receptors using a conserved binding motif sequence containing an RGD or similar motif. As a consequence, disintegrins can inhibit platelet aggregation and inhibit cell migration, proliferation, and initiate apoptosis in cancer cell lines. Rubistatin is a MVD disintegrin cloned from a Crotalus ruber ruber venom gland. The biological activity of MVD disintegrins is poorly understood. Recombinant rubistatin (r-Rub) was cloned into a pET32b plasmid and expressed in reductase-deficient Escherichia coli. Expression was induced with IPTG and the resulting fusion peptide was affinity purified, followed by thrombin cleavage, and removal of vector coded sequences. r-Rub peptide inhibited ADP-induced platelet aggregation by 54% ± 6.38 in whole blood. We assessed the ability of r-Rub to initiate apoptosis in three human cancer cell lines. Cultures of SK-Mel-28, HeLA, and T24 cells were grown for 24 h with 2.5 μM r-Rub followed by Hoechst staining. Chromatin fragmentation was observed in treated SK-Mel-28, but not in T24 or HeLA cells. A TUNEL assay revealed that 51.55% ± 5.28 of SK-Mel-28 cells were apoptotic after 18 h of treatment with 3.5 μM of r-Rub. Cell migration and proliferation assays were performed in order to further characterize the biological effects of r-Rub on SK-Mel-28 cells. At 3 μM, r-Rub inhibited cell migration by 44.4% ± 0.5, while at 3.5 μM it was able to inhibit cell proliferation by 83% ± 6.0. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Nucleic acids encoding a cellulose binding domain

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1996-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  6. Water absorption and maintenance of nanofiber cellulose ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-05-17

    May 17, 2012 ... Physiochemical properties of bacterial cellulose producing by Gluconacetobacter rhaeticus TL-2C was ... shape of the mold (Czaja et al., 2006). ... impurity, and then it was freeze-dried and ground to a fine ... Figure 1. Microstructure and chemical structure of bacterial cellulose producing G. rhaeticus TL-2C.

  7. Characterization of cellulose nanofibrillation by micro grinding

    Science.gov (United States)

    Sandeep S. Nair; J.Y. Zhu; Yulin Deng; Arthur J. Ragauskas

    2014-01-01

    A fundamental understanding of the morphological development of cellulose fibers during fibrillation using micro grinder is very essential to develop effective strategies for process improvement and to reduce energy consumption. We demonstrated some simple measures for characterizing cellulose fibers fibrillated at different fibrillation times through the grinder. The...

  8. Cellulose Triacetate Dielectric Films For Capacitors

    Science.gov (United States)

    Yen, Shiao-Ping S.; Jow, T. Richard

    1994-01-01

    Cellulose triacetate investigated for use as dielectric material in high-energy-density capacitors for pulsed-electrical-power systems. Films of cellulose triacetate metalized on one or both sides for use as substrates for electrodes and/or as dielectrics between electrodes in capacitors. Used without metalization as simple dielectric films. Advantages include high breakdown strength and self-healing capability.

  9. Modelling the elastic properties of cellulose nanopaper

    DEFF Research Database (Denmark)

    Mao, Rui; Goutianos, Stergios; Tu, Wei

    2017-01-01

    The elastic modulus of cellulose nanopaper was predicted using a two-dimensional (2D) micromechanical fibrous network model. The elastic modulus predicted by the network model was 12 GPa, which is well within the range of experimental data for cellulose nanopapers. The stress state in the network...

  10. Isolation and characterization of microcrystalline cellulose obtained ...

    African Journals Online (AJOL)

    In this study, microcrystalline cellulose, coded MCC-PNF, was obtained from palm nut (Elaeis guineensis) fibres. MCC-PNF was examined for its physicochemical and powder properties. The powder properties of MCC-PNF were compared to those of the best commercial microcrystalline cellulose grade, Avicel PH 101.

  11. Some Physical Characteristics of Microcrystalline Cellulose ...

    African Journals Online (AJOL)

    Purpose: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. This study aimed at evaluating the physical characteristics of microcrystalline cellulose (CP-MCC), obtained from the raw cotton of Cochlospermum planchonii. Methods: CP-MCC was obtained from the ...

  12. Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

    Science.gov (United States)

    Djioleu, Angele Mezindjou

    The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in the presence of switchgrass prehydrolyzates against model substrates, activities of cellulase, betaglucosidase, and exoglucanase, were significantly reduced by at least 16%, 31.8%, and 57.8%, respectively, as compared to the control. A strong positive correlation between inhibition of betaglucosidase and concentration of glucose, acetic acid, and furans in prehydrolyzate was established. Exoglucanase inhibition correlated with the presence of phenolic compounds and acetic acid. The prehydrolyzate, prepared at 160°C, 30 min, and 1% acid, was fractionated by centrifugal partition chromatography (CPC) into six fractions; the inhibition effect of these fractions on betaglucosidase and exoglucanase was determined. The initial hydrolysis rate of cellobiose by betaglucosidase was significantly reduced by the CPC sugar-rich fraction; however, exoglucanase was deactivated by the CPC phenolic-rich fraction. Finally, biological activities of water-extracted compounds from sweetgum bark and their effect on cellulase was investigated. It was determined that 12% of solid content of the bark extract could be accounted by phenolic compounds with gallic acid identified as the most concentrated phytochemical. Sweetgum bark extract inhibited Staphylococcus

  13. Plasma-enhanced synthesis of green flame retardant cellulosic materials

    Science.gov (United States)

    Totolin, Vladimir

    The natural fiber-containing fabrics and composites are more environmentally friendly, and are used in transportation (automobiles, aerospace), military applications, construction industries (ceiling paneling, partition boards), consumer products, etc. Therefore, the flammability characteristics of the composites based on polymers and natural fibers play an important role. This dissertation presents the development of plasma assisted - green flame retardant coatings for cellulosic substrates. The overall objective of this work was to generate durable flame retardant treatment on cellulosic materials. In the first approach sodium silicate layers were pre-deposited onto clean cotton substrates and cross linked using low pressure, non-equilibrium oxygen plasma. A statistical design of experiments was used to optimize the plasma parameters. The modified cotton samples were tested for flammability using an automatic 45° angle flammability test chamber. Aging tests were conducted to evaluate the coating resistance during the accelerated laundry technique. The samples revealed a high flame retardant behavior and good thermal stability proved by thermo-gravimetric analysis. In the second approach flame retardant cellulosic materials have been produced using a silicon dioxide (SiO2) network coating. SiO 2 network armor was prepared through hydrolysis and condensation of the precursor tetraethyl orthosilicate (TEOS), prior coating the substrates, and was cross linked on the surface of the substrates using atmospheric pressure plasma (APP) technique. Due to protection effects of the SiO2 network armor, the cellulosic based fibers exhibit enhanced thermal properties and improved flame retardancy. In the third approach, the TEOS/APP treatments were extended to linen fabrics. The thermal analysis showed a higher char content and a strong endothermic process of the treated samples compared with control ones, indicating a good thermal stability. Also, the surface analysis proved

  14. Natural composites: Strength, packing ability and moisture sorption of cellulose fibres, and the related performance of composites

    DEFF Research Database (Denmark)

    Lilholt, Hans; Madsen, Bo

    2012-01-01

    Biobased materials are becoming of increasing interest as potential structural materials for the future. A useful concept in this context is the fibre reinforcement of materials by stiff and strong fibres. The bio-resources can contribute with cellulose fibres and (bio) polymers from hemicelluloses...... in stiffness, on the packing ability of cellulose fibres and the related maximum fibre volume fraction in composites, on the moisture sorption of cellulose fibres and the related mass increase and (large) hygral strains induced, and on the mechanical performance of composites....

  15. Radiation pretreatment of cellulose for energy production

    Science.gov (United States)

    Dela Rosa, A. M.; Dela Mines, A. S.; Banzon, R. B.; Simbul-Nuguid, Z. F.

    The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulosic material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism.

  16. Radiation pretreatment of cellulose for energy production

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Dela Mines, A.S.; Banzon, R.B.; Simbul-Nuguid, Z.F.

    1983-01-01

    The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulose material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism. (author)

  17. Biofunctional Paper via Covalent Modification of Cellulose

    Science.gov (United States)

    Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A.; Kaplan, Justin M.; Andrade, Rodrigo B.; Ratner, Daniel M.

    2012-01-01

    Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to covalently immobilize small molecules, proteins and DNA onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane’s bioactivity was specific, dose-dependent, and stable over a long period of time. Use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices. PMID:22708701

  18. Development of composites of polycaprolactone with cellulose

    International Nuclear Information System (INIS)

    Aguiar, V.O.; Marques, M.F.V.

    2015-01-01

    In the present work, alkaline followed by an acid treatment were performed in plant sources of curaua and jute fibers to remove the amorphous portion and to aid fibrillation. Using the technique of X-ray diffraction it was observed that the chemical treatments led to a better organization of cellulose microfibrils and, consequently, the increase in their crystallinity index. Using the thermogravimetric analysis it was noted a slight decrease in thermal stability of the chemically treated cellulose fibers, however it did not impairs its use as filler in the polymer matrix. Through the SEM micrographs it was observed that the chemical treatment reduced the dimensions of the fibers in natura. Polycaprolactone composite was prepared in a twin-screw extruder at different amounts for several cellulose sources (those obtained from vegetable fibers, curaua and jute, commercial cellulose and amorphous cellulose) at and maintaining the process time and temperature constant. (author)

  19. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1985-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of low-level radioactive cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work has been completed using a 75-L digester to verify rates and conversions obtained at the bench scale. Start-up and operating procedures have been developed, and effluent was generated for characterization and disposal studies. Three runs using batch and fed-batch conditions were made lasting 36, 90, and 423 d. Solids solubilization rates and gas production rates averaged approximately 1.8 g cellulose per L of reactor per d and 1.2 L of off-gas per L reactor per d. Greater than 80% destruction of the volatile suspended solids was obtained. A simple dynamic process model was constructed to aid in process design and for use in process monitoring and control of a large-scale digester

  20. Anaerobic digestion of cellulosic wastes

    International Nuclear Information System (INIS)

    Donaldson, T.L.; Lee, D.D.

    1984-01-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 7 references, 5 figures, 1 table

  1. Cytocompatible cellulose hydrogels containing trace lignin

    International Nuclear Information System (INIS)

    Nakasone, Kazuki; Kobayashi, Takaomi

    2016-01-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm"2 and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  2. Cytocompatible cellulose hydrogels containing trace lignin

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Kazuki; Kobayashi, Takaomi, E-mail: takaomi@nagaoakut.ac.jp

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm{sup 2} and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  3. Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

    International Nuclear Information System (INIS)

    Thongekkaew, Jantaporn; Ikeda, Hiroko; Iefuji, Haruyuki

    2012-01-01

    Highlights: ► The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. ► The fusion enzyme was stable at 80 °C for 120-min. ► The fusion enzyme was responsible for cellulose-binding capacity. ► The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae (α factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS–PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 °C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

  4. Increases thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase by fusion of cellulose binding domain derived from Trichoderma reesei

    Energy Technology Data Exchange (ETDEWEB)

    Thongekkaew, Jantaporn, E-mail: jantaporn_25@yahoo.com [Department of Biological Science, Faculty of Science, Ubon-Ratchathani University, Warinchumrab, Ubon-Ratchathani 34190 (Thailand); Ikeda, Hiroko; Iefuji, Haruyuki [Application Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer The CSLP and fusion enzyme were successfully expressed in the Pichia pastoris. Black-Right-Pointing-Pointer The fusion enzyme was stable at 80 Degree-Sign C for 120-min. Black-Right-Pointing-Pointer The fusion enzyme was responsible for cellulose-binding capacity. Black-Right-Pointing-Pointer The fusion enzyme has an attractive applicant for enzyme immobilization. -- Abstract: To improve the thermal stability and cellulose-binding capacity of Cryptococcus sp. S-2 lipase (CSLP), the cellulose-binding domain originates from Trichoderma reesei cellobiohydrolase I was engineered into C-terminal region of the CSLP (CSLP-CBD). The CSLP and CSLP-CBD were successfully expressed in the Pichia pastoris using the strong methanol inducible alcohol oxidase 1 (AOX1) promoter and the secretion signal sequence from Saccharomyces cerevisiae ({alpha} factor). The recombinant CSLP and CSLP-CBD were secreted into culture medium and estimated by SDS-PAGE to be 22 and 27 kDa, respectively. The fusion enzyme was stable at 80 Degree-Sign C and retained more than 80% of its activity after 120-min incubation at this temperature. Our results also found that the fusion of fungal exoglucanase cellulose-binding domain to CSLP is responsible for cellulose-binding capacity. This attribute should make it an attractive applicant for enzyme immobilization.

  5. Eliminating inhibition of enzymatic hydrolysis by lignosulfonate in unwashed sulfite-pretreated aspen using metal salts

    Science.gov (United States)

    Hao Liu; Junyong Zhu

    2010-01-01

    This study demonstrated the efficiency of Ca(II) and Mg(II) in removing inhibition of enzymatic hydrolysis by lignosulfonate through non-productive adsorption of enzymes. Adding 1 mmol/g cellulose of either metal salt restores approximately 65% of the activity lost when a pure cellulose/cellulase solution is spiked with lignosulfonate. Addition of either Ca(II) or Mg(...

  6. fA cellular automaton model of crystalline cellulose hydrolysis by cellulases

    Directory of Open Access Journals (Sweden)

    Little Bryce A

    2011-10-01

    Full Text Available Abstract Background Cellulose from plant biomass is an abundant, renewable material which could be a major feedstock for low emissions transport fuels such as cellulosic ethanol. Cellulase enzymes that break down cellulose into fermentable sugars are composed of different types - cellobiohydrolases I and II, endoglucanase and β-glucosidase - with separate functions. They form a complex interacting network between themselves, soluble hydrolysis product molecules, solution and solid phase substrates and inhibitors. There have been many models proposed for enzymatic saccharification however none have yet employed a cellular automaton approach, which allows important phenomena, such as enzyme crowding on the surface of solid substrates, denaturation and substrate inhibition, to be considered in the model. Results The Cellulase 4D model was developed de novo taking into account the size and composition of the substrate and surface-acting enzymes were ascribed behaviors based on their movements, catalytic activities and rates, affinity for, and potential for crowding of, the cellulose surface, substrates and inhibitors, and denaturation rates. A basic case modeled on literature-derived parameters obtained from Trichoderma reesei cellulases resulted in cellulose hydrolysis curves that closely matched curves obtained from published experimental data. Scenarios were tested in the model, which included variation of enzyme loadings, adsorption strengths of surface acting enzymes and reaction periods, and the effect on saccharide production over time was assessed. The model simulations indicated an optimal enzyme loading of between 0.5 and 2 of the base case concentrations where a balance was obtained between enzyme crowding on the cellulose crystal, and that the affinities of enzymes for the cellulose surface had a large effect on cellulose hydrolysis. In addition, improvements to the cellobiohydrolase I activity period substantially improved overall

  7. Modified cellulose nanocrystal for vitamin C delivery.

    Science.gov (United States)

    Akhlaghi, Seyedeh Parinaz; Berry, Richard M; Tam, Kam Chiu

    2015-04-01

    Cellulose nanocrystal grafted with chitosan oligosaccharide (CNC-CSOS) was used to encapsulate vitamin C and prepare CNCS/VC complexes using tripolyphosphte via ionic complexation. The stability of vitamin C and the antioxidant activity of the CNCS/VC complexes were elucidated. The formation of the complex was confirmed using DSC and UV-vis spectrophotometry, and TEM was used to study the morphology of the complexes. The encapsulation efficiency of vitamin C at pH 3 and 5 was 71.6% ± 6.8 and 91.0 ± 1.0, respectively. Strong exothermic peaks observed in isothermal titration calorimetric (ITC) studies at pH 5 could be attributed to additional electrostatic interactions between CNC-CSOS and vitamin C at pH 5. The in vitro release of vitamin C from CNCS/VC complexes showed a sustained release of up to 20 days. The vitamin C released from CNCS/VC complex displayed higher stability compared with the control vitamin C solution, and this was also confirmed from the ITC thermograms. CNC-CSOS possessed a higher scavenging activity and faster antioxidant activity compared with its precursors, i.e., oxidized CNC and CSOS and their physical mixtures. Complexing vitamin C into CNC-CSOS particles yielded a dynamic antioxidant agent, where the vitamin C is released over time and displayed sustained antioxidant properties. Therefore, CNCS/VC can potentially be used in cosmeceutical applications as topical formulations.

  8. Salmonella biofilm formation on Aspergillus niger involves cellulose--chitin interactions.

    Directory of Open Access Journals (Sweden)

    Maria T Brandl

    Full Text Available Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to and forms biofilms on the hyphae of the common fungus, Aspergillus niger. Several Salmonella enterica serovars displayed a similar interaction, whereas other bacterial species were unable to bind to the fungus. Bacterial attachment to chitin, a major constituent of fungal cell walls, mirrored this specificity. Pre-incubation of S. Typhimurium with N-acetylglucosamine, the monomeric component of chitin, reduced binding to chitin beads by as much as 727-fold and inhibited attachment to A. niger hyphae considerably. A cellulose-deficient mutant of S. Typhimurium failed to attach to chitin beads and to the fungus. Complementation of this mutant with the cellulose operon restored binding to chitin beads to 79% of that of the parental strain and allowed for attachment and biofilm formation on A. niger, indicating that cellulose is involved in bacterial attachment to the fungus via the chitin component of its cell wall. In contrast to cellulose, S. Typhimurium curli fimbriae were not required for attachment and biofilm development on the hyphae but were critical for its stability. Our results suggest that cellulose-chitin interactions are required for the production of mixed Salmonella-A. niger biofilms, and support the hypothesis that encounters with chitinaceous alternate hosts may contribute to the ecological success of human pathogens.

  9. Use of hydroxyurea in the measurement of DNA repair by the BND cellulose method

    International Nuclear Information System (INIS)

    Irwin, J.; Strauss, B.

    1980-01-01

    Hydroxyurea inhibition is a convenient method of suppressing replicative DNA synthesis for DNA excision-repair measurement by the BND cellulose technique. Nonetheless, hydroxyurea can introduce artefacts by direct reaction with repair-inducing compounds and by long-term inhibition of the overall repair process. A simple technique of overcoming these problems is described. Cells are reacted with repair-inducing compounds in the absence of hydroxyurea, the cells are washed free of inducer, hydroxyurea is added to 2 mM, and after a short period to establish replication inhibition, 3 H dThd is added and repair measured over a one-hour incubation period

  10. Cellulose-Based Nanomaterials for Energy Applications.

    Science.gov (United States)

    Wang, Xudong; Yao, Chunhua; Wang, Fei; Li, Zhaodong

    2017-11-01

    Cellulose is the most abundant natural polymer on earth, providing a sustainable green resource that is renewable, degradable, biocompatible, and cost effective. Recently, nanocellulose-based mesoporous structures, flexible thin films, fibers, and networks are increasingly developed and used in photovoltaic devices, energy storage systems, mechanical energy harvesters, and catalysts components, showing tremendous materials science value and application potential in many energy-related fields. In this Review, the most recent advancements of processing, integration, and application of cellulose nanomaterials in the areas of solar energy harvesting, energy storage, and mechanical energy harvesting are reviewed. For solar energy harvesting, promising applications of cellulose-based nanostructures for both solar cells and photoelectrochemical electrodes development are reviewed, and their morphology-related merits are discussed. For energy storage, the discussion is primarily focused on the applications of cellulose-based nanomaterials in lithium-ion batteries, including electrodes (e.g., active materials, binders, and structural support), electrolytes, and separators. Applications of cellulose nanomaterials in supercapacitors are also reviewed briefly. For mechanical energy harvesting, the most recent technology evolution in cellulose-based triboelectric nanogenerators is reviewed, from fundamental property tuning to practical implementations. At last, the future research potential and opportunities of cellulose nanomaterials as a new energy material are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Enhancement of Cellulose Degradation by Cattle Saliva

    Science.gov (United States)

    Seki, Yasutaka; Kikuchi, Yukiko; Kimura, Yoshihiro; Yoshimoto, Ryo; Takahashi, Masatoshi; Aburai, Kenichi; Kanai, Yoshihiro; Ruike, Tatsushi; Iwabata, Kazuki; Sugawara, Fumio; Sakai, Hideki; Abe, Masahiko; Sakaguchi, Kengo

    2015-01-01

    Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale. PMID:26402242

  12. Enzymatic Cellulose Palmitate Synthesis Using Immobilized Lipase

    Directory of Open Access Journals (Sweden)

    Anna Roosdiana

    2017-06-01

    Full Text Available Bacterial cellulose can be modified by esterification using palmitic acid and Mucor miehei  lipase  as catalyst. The purpose of this research was to determine the optimum conditions of esterification reaction of cellulose and palmitic acid . The esterification reaction was carried out at the time variation  of  6, 12, 18, 24 and 30 hours and the mass ratio of cellulose: palmitic acid (1: 11: 2, 1: 3, 1: 4, 1: 5,1:6 at 50 °C. The   cellulose palmitate  was examined  its  physical and chemical properties by using FTIR spectrophotometer, XRD, bubble point test and saponification  apparatus. The results showed that the optimum reaction time of esterification reaction of cellulose and palmitic acid occurred within 24 hours and the mass ratio of cellulose: palmitic acid was 1: 3 resulting in DS of  0.376 with  swelling index of 187 %, crystallinity index of 61.95%,  and Φ porous of 2.40 μm. Identification of functional groups using FTIR spectrophotometer showed that C=O ester group  was observed at 1737.74 cm-1 and strengthened  by  the appearance of C-O ester peak at 1280 cm-1. The conclusion of this study is reaction time and reactant ratio influence significantly the DS of cellulose ester.

  13. Model films of cellulose. I. Method development and initial results

    NARCIS (Netherlands)

    Gunnars, S.; Wågberg, L.; Cohen Stuart, M.A.

    2002-01-01

    This report presents a new method for the preparation of thin cellulose films. NMMO (N- methylmorpholine- N-oxide) was used to dissolve cellulose and addition of DMSO (dimethyl sulfoxide) was used to control viscosity of the cellulose solution. A thin layer of the cellulose solution is spin- coated

  14. Overview of Cellulose Nanomaterials, Their Capabilities and Applications

    Science.gov (United States)

    Robert J. Moon; Gregory T. Schueneman; John Simonsen

    2016-01-01

    Cellulose nanomaterials (CNs) are a new class of cellulose particles with properties and functionalities distinct from molecular cellulose and wood pulp, and as a result, they are being developed for applications that were once thought impossible for cellulosic materials. Momentum is growing in CN research and development, and commercialization in this field is...

  15. Prevalence and trends of cellulosics in pharmaceutical dosage forms.

    Science.gov (United States)

    Mastropietro, David J; Omidian, Hossein

    2013-02-01

    Many studies have shown that cellulose derivatives (cellulosics) can provide various benefits when used in virtually all types of dosage forms. Nevertheless, the popularity of their use in approved drug products is rather unknown. This research reports the current prevalence and trends of use for 15 common cellulosics in prescription drug products. The cellulosics were powdered and microcrystalline cellulose (MCC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), hypromellose (HPMC), HPMC phthalate, HPMC acetate succinate, cellulose acetate (CA), CA phthalate, sodium (Na) and calcium (Ca) carboxymethylcellulose (CMC), croscarmellose sodium (XCMCNa), methyl cellulose, and low substituted HPC. The number of brand drug products utilizing each cellulosics was determined using the online drug index Rxlist. A total of 607 brand products were identified having one or more of the cellulosics as an active or inactive ingredient. An array of various dosage forms was identified and revealed HPMC and MCC to be the most utilized cellulosics in all products followed by XCMCNa and HPC. Many products contained two or more cellulosics in the formulation (42% containing two, 23% containing three, and 4% containing 4-5). The largest combination occurrence was HPMC with MCC. The use of certain cellulosics within different dosage form types was found to contain specific trends. All injectables utilized only CMCNa, and the same with all ophthalmic solutions utilizing HPMC, and otic suspensions utilizing HEC. Popularity and trends regarding cellulosics use may occur based on many factors including functionality, safety, availability, stability, and ease of manufacturing.

  16. Preparation of carboxymethyl cellulose produced from purun tikus (Eleocharis dulcis)

    Science.gov (United States)

    Sunardi, Febriani, Nina Mutia; Junaidi, Ahmad Budi

    2017-08-01

    Sodium carboxymethyl cellulose (Na-CMC) is one of the important modified cellulose, a water-soluble cellulose, which is widely used in many application of food, pharmaceuticals, detergent, paper coating, dispersing agent, and others. The main raw material of modified cellulose is cellulose from wood and cotton. Recently, much attention has been attracted to the use of various agriculture product and by-product, grass, and residual biomass as cellulose and modified cellulose source for addressing an environmental and economic concern. Eleocharis dulcis, commonly known as purun tikus (in Indonesia), is a native aquatic plant of swamp area (wetland) in Kalimantan, which consists of 30-40% cellulose. It is significantly considered as one of the alternative resources for cellulose. The aims of present study were to isolate cellulose from E. dulcis and then to synthesise Na-CMC from isolated cellulose. Preparation of carboxymethyl cellulose from E. dulcis was carried out by an alkalization and etherification process of isolated cellulose, using various concentration of sodium hydroxide (NaOH) and monochloroacetic acid (MCA). The results indicated that the optimum reaction of alkalization was reached at 20% NaOH and etherification at the mass fraction ratio of MCA to cellulose 1.0. The optimum reaction has the highest solubility and degree of substitution. The carboxymethylation process of cellulose was confirmed by Fourier Transform Infrared spectroscopy (FTIR). In addition, changes in crystallinity of cellulose and Na-CMC were evaluated by X-ray diffraction (XRD).

  17. Dual-skinned polyamide/poly(vinylidene fluoride)/cellulose acetate membranes with embedded woven

    KAUST Repository

    Phuoc, Duong; Nunes, Suzana Pereira; Chung, Tai-Shung

    2016-01-01

    strength, (iii) a strong woven fabric, and (iv) fouling resistant porous cellulose acetate (CA) layer. The PA layer rejects solutes of the draw solution. The PVDF/woven fabric/CA (PVDF/CA) integrated layer performs as a mechanical support with unique

  18. Evaluation of reactive force fields for prediction of the thermo-mechanical properties of cellulose

    Science.gov (United States)

    Fernando L. Dri; Xiawa Wu; Robert J. Moon; Ashlie Martini; Pablo D. Zavattieri

    2015-01-01

    Molecular dynamics simulation is commonly used to study the properties of nanocellulose-based materials at the atomic scale. It is well known that the accuracy of these simulations strongly depends on the force field that describes energetic interactions. However, since there is no force field developed specifically for cellulose, researchers utilize models...

  19. Cellulosic ethanol: status and innovation

    Energy Technology Data Exchange (ETDEWEB)

    Lynd, Lee R.; Liang, Xiaoyu; Biddy, Mary J.; Allee, Andrew; Cai, Hao; Foust, Thomas; Himmel, Michael E.; Laser, Mark S.; Wang, Michael; Wyman, Charles E.

    2017-06-01

    Although the purchase price of cellulosic feedstocks is competitive with petroleum on an energy basis, the cost of lignocellulose conversion to ethanol using today’s technology is high. Cost reductions can be pursued via either in-paradigm or new-paradigm innovation. As an example of new-paradigm innovation, consolidated bioprocessing using thermophilic bacteria combined with milling during fermentation (cotreatment) is analyzed. Acknowledging the nascent state of this approach, our analysis indicates potential for radically improved cost competitiveness and feasibility at smaller scale compared to current technology, arising from (a) R&D-driven advances (consolidated bioprocessing with cotreatment in lieu of thermochemical pretreatment and added fungal cellulase), and (b) configurational changes (fuel pellet coproduction instead of electricity, gas boiler(s) in lieu of a solid fuel boiler).

  20. Characterization of ethyl cellulose polymer.

    Science.gov (United States)

    Mahnaj, Tazin; Ahmed, Salah U; Plakogiannis, Fotios M

    2013-01-01

    Ethyl cellulose (EC) polymer was characterized for its property before considering the interactions with the plasicizer. Ethocel Std.10 FP Premium from Dow chemical company USA was tested for its solubility, morphology and thermal properties. Seven percentage of EC solution in ethanol was found to be the right viscosity used to prepare the film. The EC polymer and EC film without any plasticizers showed almost identical thermal behavior, but in X-ray diffraction showed different arrangements of crystallites and amorphous region. Dynamic mechanical analysis of film showed that without a plasticizer, EC film was not flexible and had very low elongation with high applied force. The aim of the work was to avoid using the commercially available EC dispersions Surelease® and Aquacoat®; both already have additives on it. Instead, Ethocel EC polymer (powder) was characterized in our laboratory in order to find out the properties of polymer before considering the interactions of the polymer with various plasticizers.

  1. Preparation of membranes from cellulose obtained of sugarcane bagasse

    International Nuclear Information System (INIS)

    Pereira, Paulo Henrique Fernandes; Cioffi, Maria Odila Hilario; Voorwald, Herman Jacobus Cornelis; Pinho, Maria Noberta de; Silva, Maria Lucia Caetano Pinto da

    2010-01-01

    In this work, cellulose obtained from sugarcane bagasse to produce both cellulose and acetylated cellulose to prepare asymmetric membranes. Membranes was procedure used a mixture of materials of DMAc/ LiCl systemic in different conditions. Cellulose and acetylated cellulose were characterized by thermogravimetric (TG), Xray diffraction (XRD) and scanning Electron Microscopy (SEM). Observed less stability thermal of acetylated cellulose when compared of cellulose. All membranes procedure were asymmetric, characterized by presence of a dense skin and porous support can be observed. SEM showed that the morphology of the superficial of membranes depends on the method preparation. (author)

  2. Enzymic hydrolysis of cellulosic wastes to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Spano, L A; Medeiros, J; Mandels, M

    1976-01-01

    An enzymic process for the conversion of cellulose to glucose is based on the use of a specific enzyme derived from mutant strains of the fungus trichoderma viride which is capable of reacting with the crystalline fraction of the cellulose molecule. The production and mode of action of the cellulase complex produced during the growth of trichoderma viride is discussed as well as the application of such enzymes for the conversion of cellulosic wastes to crude glucose syrup for use in production of chemical feedstocks, single-cell proteins, fuels, solvents, etc.

  3. Degradation of cellulosic substances by Thermomonospora curvata

    Energy Technology Data Exchange (ETDEWEB)

    Stutzenberger, F J

    1979-05-01

    Research is reported on the cellulolytic activity of Thermomonospora curvata, a thermophilic cellulolytic actinomycete prevalent in municipal solid waste compost. Various cellulosic wastes were evaluated for their potential for the induction of cellulase synthesis by Th. curvata and the extent of cellulose degradation under optimal culture conditions. All the substrates tested showed significant degradation of their cellulose content with the exception of sawdust and barley straw. In contrast to Trichoderma viride, cotton fibers were the best substrates for both C/sub 1/ and C/sub x/ cellulase production. Further research is recommended. (JSR)

  4. Homogeneous preparation of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from sugarcane bagasse cellulose in ionic liquid.

    Science.gov (United States)

    Huang, Kelin; Wang, Ben; Cao, Yan; Li, Huiquan; Wang, Jinshu; Lin, Weijiang; Mu, Chaoshi; Liao, Dankui

    2011-05-25

    Cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP) were prepared homogeneously in a 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid system from sugarcane bagasse (SB). The reaction temperature, reaction time, and molar ratio of butyric (propionic) anhydride/anhydroglucose units in the cellulose affect the butyryl (B) or propionyl (P) content of CAB or CAP samples. The (13)C NMR data revealed the distribution of the substituents of CAB and CAP. The thermal stability of sugar cane bagasse cellulose was found by thermogravimetric analysis to have decreased after chemical modification. After reaction, the ionic liquid was effectively recycled and reused. This study provides a new way for high-value-added utilization of SB and realizing the objective of turning waste into wealth.

  5. Brittle Culm1, a COBRA-Like Protein, Functions in Cellulose Assembly through Binding Cellulose Microfibrils

    Science.gov (United States)

    Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

    2013-01-01

    Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity. PMID:23990797

  6. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Directory of Open Access Journals (Sweden)

    Lifeng Liu

    Full Text Available Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1, a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  7. Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.

    Science.gov (United States)

    Liu, Lifeng; Shang-Guan, Keke; Zhang, Baocai; Liu, Xiangling; Yan, Meixian; Zhang, Lanjun; Shi, Yanyun; Zhang, Mu; Qian, Qian; Li, Jiayang; Zhou, Yihua

    2013-01-01

    Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.

  8. Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis1[OPEN

    Science.gov (United States)

    Rui, Yue; Anderson, Charles T.

    2016-01-01

    Stomatal guard cells are pairs of specialized epidermal cells that control water and CO2 exchange between the plant and the environment. To fulfill the functions of stomatal opening and closure that are driven by changes in turgor pressure, guard cell walls must be both strong and flexible, but how the structure and dynamics of guard cell walls enable stomatal function remains poorly understood. To address this question, we applied cell biological and genetic analyses to investigate guard cell walls and their relationship to stomatal function in Arabidopsis (Arabidopsis thaliana). Using live-cell spinning disk confocal microscopy, we measured the motility of cellulose synthase (CESA)-containing complexes labeled by green fluorescent protein (GFP)-CESA3 and observed a reduced proportion of GFP-CESA3 particles colocalizing with microtubules upon stomatal closure. Imaging cellulose organization in guard cells revealed a relatively uniform distribution of cellulose in the open state and a more fibrillar pattern in the closed state, indicating that cellulose microfibrils undergo dynamic reorganization during stomatal movements. In cesa3je5 mutants defective in cellulose synthesis and xxt1 xxt2 mutants lacking the hemicellulose xyloglucan, stomatal apertures, changes in guard cell length, and cellulose reorganization were aberrant during fusicoccin-induced stomatal opening or abscisic acid-induced stomatal closure, indicating that sufficient cellulose and xyloglucan are required for normal guard cell dynamics. Together, these results provide new insights into how guard cell walls allow stomata to function as responsive mediators of gas exchange at the plant surface. PMID:26729799

  9. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  10. Kinetics of Cellulose Digestion by Fibrobacter succinogenes S85

    OpenAIRE

    Maglione, G.; Russell, J. B.; Wilson, D. B.

    1997-01-01

    Growing cultures of Fibrobacter succinogenes S85 digested cellulose at a rapid rate, but nongrowing cells and cell extracts did not have detectable crystalline cellulase activity. Cells that had been growing exponentially on cellobiose initiated cellulose digestion and succinate production immediately, and cellulose-dependent succinate production could be used as an index of enzyme activity against crystalline cellulose. Cells incubated with cellulose never produced detectable cellobiose, and...

  11. Chitosan-based microcapsules containing grapefruit seed extract grafted onto cellulose fibers by a non-toxic procedure.

    Science.gov (United States)

    Alonso, Diana; Gimeno, Miquel; Sepúlveda-Sánchez, José D; Shirai, Keiko

    2010-04-19

    A novel non-toxic procedure is described for the grafting of chitosan-based microcapsules containing grapefruit seed oil extract onto cellulose. The cellulose was previously UV-irradiated and then functionalized from an aqueous emulsion of the chitosan with the essential oil. The novel materials are readily attained with durable fragrance and enhanced antimicrobial properties. The incorporation of chitosan as determined from the elemental analyses data was 16.08+/-0.29 mg/g of sample. Scanning electron microscopy (SEM) and gas chromatography-mass spectroscopy (GC-MS) provided further evidence for the successful attachment of chitosan microcapsules containing the essential oil to the treated cellulose fibers. The materials thus produced displayed 100% inhibition of Escherichia coli and Staphylococcus epidermidis up to 48 h of incubation. Inhibition of bacteria by the essential oil was also evaluated at several concentrations. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  12. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    International Nuclear Information System (INIS)

    Fu, Jiapeng; Pang, Zengyuan; Yang, Jie; Huang, Fenglin; Cai, Yibing; Wei, Qufu

    2015-01-01

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors

  13. Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

    Directory of Open Access Journals (Sweden)

    Anand Kumar Veeramachineni

    2016-06-01

    Full Text Available Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA, Infrared Spectroscopy (FTIR, X-Ray Diffraction (XRD, Differential Scanning Calorimetry (DSC and Field Emission Scanning Electronic Microscopy (FESEM. The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

  14. Fabrication of polyaniline/carboxymethyl cellulose/cellulose nanofibrous mats and their biosensing application

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiapeng, E-mail: firgexiao@sina.cn; Pang, Zengyuan, E-mail: pangzengyuan1212@163.com; Yang, Jie, E-mail: young1993@126.com; Huang, Fenglin, E-mail: flhuang@jiangnan.edu.cn; Cai, Yibing, E-mail: yibingcai@jiangnan.edu.cn; Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn

    2015-09-15

    Graphical abstract: - Highlights: • PANI nanorods have been grown onto the surface of CMC/cellulose nanofibers for the fabrication of biosensor substrate material. • The proposed laccase biosensor exhibited a low detection limit and high sensitivity in the detection of catechol. • Hierarchical PANI/CMC/cellulose nanofibers are the promising material in the design of high-efficient biosensors. - Abstract: We report a facile approach to synthesizing and immobilizing polyaniline nanorods onto carboxymethyl cellulose (CMC)-modified cellulose nanofibers for their biosensing application. Firstly, the hierarchical PANI/CMC/cellulose nanofibers were fabricated by in situ polymerization of aniline on the CMC-modified cellulose nanofiber. Subsequently, the PANI/CMC/cellulose nanofibrous mat modified with laccase (Lac) was used as biosensor substrate material for the detection of catechol. PANI/CMC/cellulose nanofibers with highly conductive and three dimensional nanostructure were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under optimum conditions, the Lac/PANI/CMC/cellulose/glassy carbon electrode (GCE) exhibited a fast response time (within 8 s), a linear response range from 0.497 μM to 2.27 mM with a high sensitivity and low detection limit of 0.374 μM (3σ). The developed biosensor also displayed good repeatability, reproducibility as well as selectivity. The results indicated that the composite mat has potential application in enzyme biosensors.

  15. Ethanol production from cellulose, lactose and xylose using yeasts and enzymes. Gewinnung von Ethanol aus Cellulose, Lactose, und Xylose mit Hilfe von Hefen und Enzymen

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, U

    1986-07-03

    Experiments with mixtures of whey and corn showed that more than 85% of the lactose was degraded into ethanol. The applicability of cellulose was investigated by means of potatoes. Cellulase is inhibited by glucose, which is a fermentation intermediate, as well as by the end product ethanol. A cellulase inhibitor in potatoes was detected and stabilized; this inhibitor could be degraded into neutral components by a suitable enzyme. Saccharification and fermentation experiments showed that the cellulose fraction of potatoes can be reduced efficiently. The effects of non-enzymatic pretreatment on enzymatic degradation of cellulose, combined with fermentation of the degradation products, are illustrated by the example of cellulose treated with acid and alkaline substances. A continuous fermentation system was developed from which the ethanol is withdrawn in vapour form. The system made better use of the cellulase activity and increased the efficiency of a xylose-fermenting yeast. The new method is compared with batch experiments in order to assess its efficiency. The advantages of the continuous process are proved for two yeasts of the species Pachysolu and Pichia. Specific fermentation rates up to 0.08 g/(g x h) and fermentation yields up to 0.42 g ethanol/g xylose were achieved with Pichia stipitis.

  16. Effects of Lytic Polysaccharide Monooxygenase Oxidation on Cellulose Structure and Binding of Oxidized Cellulose Oligomers to Cellulases

    Energy Technology Data Exchange (ETDEWEB)

    Vermaas, Josh V.; Crowley, Michael F.; Beckham, Gregg T.; Payne, Christina M.

    2015-05-21

    with different affinities relative to cellobiose itself, which potentially affects hydrolytic turnover through product inhibition. To examine the effect of oxidation on cello-oligomer binding, we use thermodynamic integration to compute the relative change in binding free energy between the hydrolyzed and oxidized products in the active site of Family 7 and Family 6 processive glycoside hydrolases, Trichoderma reesei Cel7A and Cel6A, which are key industrial cellulases and commonly used model systems for fungal cellulases. Our results suggest that the equilibrium between the two reducing end oxidized products, favoring the linear aldonic acid, may increase product inhibition, which would in turn reduce processive substrate turnover. In the case of LMPO action at the nonreducing end, oxidation appears to lower affinity with the nonreducing end specific cellulase, reducing product inhibition and potentially promoting processive cellulose turnover. Overall, this suggests that oxidation of recalcitrant polysaccharides by LPMOs accelerates degradation not only by increasing the concentration of chain termini but also by reducing decrystallization work, and that product inhibition may be somewhat reduced as a result.

  17. Conformations and Intermolecular Interactions in Cellulose/Silk Fibroin Blend Films: A Solid-State NMR Perspective.

    Science.gov (United States)

    Tian, Donglin; Li, Tao; Zhang, Rongchun; Wu, Qiang; Chen, Tiehong; Sun, Pingchuan; Ramamoorthy, Ayyalusamy

    2017-06-29

    Fabricating materials with excellent mechanical performance from the natural renewable and degradable biopolymers has drawn significant attention in recent decades due to the environmental concerns and energy crisis. As two of the most promising substitutes of synthetic polymers, silk fibroin (SF), and cellulose, have been widely used in the field of textile, biomedicine, biotechnology, etc. Particularly, the cellulose/SF blend film exhibits better strength and toughness than that of regenerated cellulose film. Herein, this study is aimed to understand the molecular origin of the enhanced mechanical properties for the cellulose/SF blend film, using solid-state NMR as a main tool to investigate the conformational changes, intermolecular interactions between cellulose and SF and the water organization. It is found that the content of the β-sheet structure is increased in the cellulose/SF blend film with respect to the regenerated SF film, accompanied by the reduction of the content of random coil structures. In addition, the strong hydrogen bonding interaction between the SF and cellulose is clearly elucidated by the two-dimensional (2D) 1 H- 13 C heteronuclear correlation (HETCOR) NMR experiments, demonstrating that the SF and cellulose are miscible at the molecular level. Moreover, it is also found that the -NH groups of SF prefer to form hydrogen bonds with the hydroxyl groups bonded to carbons C2 and C3 of cellulose, while the hydroxyl groups bonded to carbon C6 and the ether oxygen are less favorable for hydrogen bonding interactions with the -NH groups of SF. Interestingly, bound water is found to be present in the air-dried cellulose/SF blend film, which is predominantly associated with the cellulose backbones as determined by 2D 1 H- 13 C wide-line-separation (WISE) experiments with spin diffusion. This clearly reveals the presence of nanoheterogeneity in the cellulose/SF blend film, although cellulose and SF are miscible at a molecular level. Without doubt

  18. Structural and morphological characterization of cellulose pulp

    CSIR Research Space (South Africa)

    Ocwelwang, A

    2015-09-01

    Full Text Available Understanding the structure of cellulose is of utmost importance in order to enhance its accessibility and reactivity to chemical processing. Therefore, the aim of this study was to evaluate the effect of ultrasound pretreatment on the structure...

  19. diffusion of metronidazole released through cellulose membrane

    African Journals Online (AJOL)

    prof kokwaro

    was determined using dialyzing cellulose membrane in a dissolution tester. Glycerin, a permeation ... An attempt has been made in the present ... Materials. Metronidazole USP was donated by Cosmos. Pharmaceutical Ltd., Nairobi, Kenya.

  20. Cellulosic ethanol is ready to go

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M. [SunOpta BioProcess Group, Brampton, ON (Canada)

    2006-07-01

    A corporate overview of the SunOpta organization was presented. The organization includes three divisions, notably organic food, industrial minerals, and a bioprocess group. It is a Canadian organization that has experienced over 60 per cent growth per year since 1999. The presentation provided a history of the bioprocess group from 1973 to 2003. The presentation also illustrated the biomass process from wood, straw or corn stover to cellulosic ethanol and acetone and butanol. Several images were presented. The production of xylitol from oat hulls and birch and from ryegrass straw to linerboard was also illustrated. Last, the presentation illustrated the biomass production of cellulose, hemicellulose and lignin extraction as well as the ammonia pretreatment of cellulosics. The presentation also listed several current and future developments such as an expansion plan and implementation of cellulosic ethanol. Economic success was defined as requiring proximity to market; high percentage concentration to distillation; and co-located within existing infrastructure. figs.

  1. Characterization of TEMPO-oxidized bacterial cellulose

    International Nuclear Information System (INIS)

    Nascimento, Eligenes S.; Pereira, Andre L.S.; Lima, Helder L.; Barroso, Maria K. de A.; Barros, Matheus de O.; Morais, Joao P.S.; Borges, Maria de F.; Rosa, Morsyleide de F.

    2015-01-01

    The aim of this study was to characterize the TEMPO-oxidized bacterial cellulose, as a preliminary research for further application in nanocomposites. Bacterial cellulose (BC) was selectively oxidized at C-6 carbon by TEMPO radical. Oxidized bacterial cellulose (BCOX) was characterized by TGA, FTIR, XRD, and zeta potential. BCOX suspension was stable at pH 7.0, presented a crystallinity index of 83%, in spite of 92% of BC, because of decrease in the free hydroxyl number. FTIR spectra showed characteristic BC bands and, in addition, band of carboxylic group, proving the oxidation. BCOX DTG showed, in addition to characteristic BC thermal events, a maximum degradation peak at 233 °C, related to sodium anhydro-glucuronate groups formed during the cellulose oxidation. Thus, BC can be TEMPO-oxidized without great loss in its structure and properties. (author)

  2. Radiation and enzyme degradation of cellulose materials

    International Nuclear Information System (INIS)

    Duchacek, V.

    1983-01-01

    The results are summed up of a study of the effect of gamma radiation on pure cellulose and on wheat straw. The irradiation of cellulose yields acid substances - formic acid and polyhydroxy acids, toxic malondialdehyde and the most substantial fraction - the saccharides xylose, arabinose, glucose and certain oligosaccharides. A ten-fold reduction of the level of cellulose polymerization can be caused by relatively small doses - (up to 250 kGy). A qualitative analysis was made of the straw before and after irradiation and it was shown that irradiation had no significant effect on the qualitative composition of the straw. A 48 hour enzyme hydrolysis of the cellulose and straw were made after irradiation and an economic evaluation of the process was made. Radiation pretreatment is technically and economically advantageous; the production of fodder using enzyme hydrolysis of irradiated straw is not economically feasible due to the high cost of the enzyme. (M.D.)

  3. Rapid hydrolysis of celluloses in homogeneous solution

    Energy Technology Data Exchange (ETDEWEB)

    Garves, K

    1979-01-01

    Dissolution of cellulose (I), cotton, and cotton linters in a mixture of Ac0H, Ac/sub 2/O, H/sub 2/SO/sub 4/, and DMF at 120 to 160 degrees resulted in rapid and complete hydrolysis of I with decomposition of the cellulose acetatesulfate formed by gradual addition of aqueous acid. Highly crystalline I is quickly decomposed to glucose with minimum byproduct formation. Carbohydrate products containing sugar units other than glucose are hydrolyzed with destruction of monosaccharides.

  4. Alcohol for cellulosic material using plural ferments

    Energy Technology Data Exchange (ETDEWEB)

    Hoge, W H

    1977-02-22

    A process is described for producing ethanol (EtOH) from cellulosic materials by first hydrolyzing the material to sugars and then converting the sugars to alcohol by digestion and fermentation. Thus, fibrous cellulosic material obtained from municipal waste slurry was sterilized by autoclaving, followed by inoculation with Trichoderma viride cellulase and Saccharomyces cerevisiae. From 100 g of raw material, 25 mL of 95% EtOH was produced by this method.

  5. Enhancing antibacterium and strength of cellulosic paper by coating triclosan-loaded nanofibrillated cellulose (NFC).

    Science.gov (United States)

    Liu, Kai; Chen, Lihui; Huang, Liulian; Ni, Yonghao; Sun, Bo

    2015-03-06

    The nanofibrillated cellulose (NFC) was used as substrates to carry triclosan (TCS), which was then applied as a coating agent for impacting antibacterial property to paper while also improving its strength. The TCS-loaded NFC material was further characterized. UV-vis spectra results showed that a characteristic absorption band at 282 nm was observed, which was attributed to triclosan, confirming its successful loading onto NFC. The antibacterial activity tests indicated that the coated paper exhibited excellent antibacterial activity against Escherichia coli, and the growth inhibition of bacteria (GIB) increased as the loading amount of triclosan coated on paper increased. The GIB can reach 98.7% when the 0.023 g TCS-loaded NFC was coated on paper. Meanwhile, the tensile and tear index of the coated paper increased by 18.0% and 26.4%, respectively compared to the blank paper. Therefore, the triclosan-loaded paper could be potentially used in the medical field. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Isolation of cellulose microfibrils - An enzymatic approach

    Directory of Open Access Journals (Sweden)

    Sain, M.

    2006-11-01

    Full Text Available Isolation methods and applications of cellulose microfibrils are expanding rapidly due to environmental benefits and specific strength properties, especially in bio-composite science. In this research, we have success-fully developed and explored a novel bio-pretreatment for wood fibre that can substantially improve the microfibril yield, in comparison to current techniques used to isolate cellulose microfibrils. Microfibrils currently are isolated in the laboratory through a combination of high shear refining and cryocrushing. A high energy requirement of these procedures is hampering momentum in the direction of microfibril isolation on a sufficiently large scale to suit potential applications. Any attempt to loosen up the microfibrils by either complete or partial destruction of the hydrogen bonds before the mechanical process would be a step forward in the quest for economical isolation of cellulose microfibrils. Bleached kraft pulp was treated with OS1, a fungus isolated from Dutch Elm trees infected with Dutch elm disease, under different treatment conditions. The percentage yield of cellulose microfibrils, based on their diameter, showed a significant shift towards a lower diameter range after the high shear refining, compared to the yield of cellulose microfibrils from untreated fibres. The overall yield of cellulose microfibrils from the treated fibres did not show any sizeable decrease.

  7. Biohydrogen, bioelectricity and bioalcohols from cellulosic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nissila, M.

    2013-03-01

    The demand for renewable energy is increasing due to increasing energy demand and global warming associated with increasing use of fossil fuels. Renewable energy can be derived from biological production of energy carriers from cellulosic biomass. These biochemical processes include biomass fermentation to hydrogen, methane and alcohols, and bioelectricity production in microbial fuel cells (MFCs). The objective of this study was to investigate the production of different energy carriers (hydrogen, methane, ethanol, butanol, bioelectricity) through biochemical processes. Hydrogen production potential of a hot spring enrichment culture from different sugars was determined, and hydrogen was produced continuously from xylose. Cellulolytic and hydrogenic cultures were enriched on cellulose, cellulosic pulp materials, and on silage at different process conditions. The enrichment cultures were further characterized. The effect of acid pretreatment on hydrogen production from pulp materials was studied and compared to direct pulp fermentation to hydrogen. Electricity and alcohol(s) were simultaneously produced from xylose in MFCs and the exoelectrogenic and alcohologenic enrichment cultures were characterized. In the end, the energy yields obtained from different biochemical processes were determined and compared. In this study, cultures carrying out simultaneous cellulose hydrolysis and hydrogen fermentation were enriched from different sources at different operational conditions. These cultures were successfully utilized for cellulose to hydrogen fermentation in batch systems. Based on these results further research should be conducted on continuous hydrogen production from cellulosic materials.

  8. Current characterization methods for cellulose nanomaterials.

    Science.gov (United States)

    Foster, E Johan; Moon, Robert J; Agarwal, Umesh P; Bortner, Michael J; Bras, Julien; Camarero-Espinosa, Sandra; Chan, Kathleen J; Clift, Martin J D; Cranston, Emily D; Eichhorn, Stephen J; Fox, Douglas M; Hamad, Wadood Y; Heux, Laurent; Jean, Bruno; Korey, Matthew; Nieh, World; Ong, Kimberly J; Reid, Michael S; Renneckar, Scott; Roberts, Rose; Shatkin, Jo Anne; Simonsen, John; Stinson-Bagby, Kelly; Wanasekara, Nandula; Youngblood, Jeff

    2018-04-23

    A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of high-performance material applications. However, with this exponential growth in interest/activity, the development of measurement protocols necessary for consistent, reliable and accurate materials characterization has been outpaced. These protocols, developed in the broader research community, are critical for the advancement in understanding, process optimization, and utilization of CNMs in materials development. This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose nanofibrils.

  9. Effect of cellulose nanocrystals from corn cob with dispersion agent polyvinyl pyrrolidone in natural rubber latex film after aging treatment

    Science.gov (United States)

    Harahap, H.; Ridha, M.; Halimatuddahliana; Taslim; Iriany

    2018-02-01

    This study about the resistance of natural rubber latex films using nanocrystals cellulose filler from corn cob waste by aging treatment. Corn cob used as organic filler composed of cellulose, hemicellulose, and lignin. Each component has a potential for reuse, such as cellulose. Cellulose from corn cob has potential application as a filler prepared by hydrolysis process using a strong acid. The producing of natural rubber latex films through coagulant dowsing process. This research started with the pre-vulcanization process of natural rubber latex at 70 °C and followed by process of vulcanization at 110 °C for 20 minutes. Natural rubber latex films that have been produced continued with the aging treatment at 70 °C for 168 hours. The mechanical properties of natural rubber latex films after aging treatment are the tensile strength, elongation at break, M100 and M300 have performed.

  10. Synthesis of flexible magnetic nanohybrid based on bacterial cellulose under ultrasonic irradiation

    International Nuclear Information System (INIS)

    Zheng, Yi; Yang, Jingxuan; Zheng, Weili; Wang, Xiao; Xiang, Cao; Tang, Lian; Zhang, Wen; Chen, Shiyan; Wang, Huaping

    2013-01-01

    Flexible magnetic membrane based on bacterial cellulose (BC) was successfully prepared by in-situ synthesis of the Fe 3 O 4 nanoparticles under different conditions and its properties were characterized. The results demonstrated that the Fe 3 O 4 nanoparticles coated with PEG were well homogeneously dispersed in the BC matrix under ultrasonic irradiation with the saturation magnetization of 40.58 emu/g. Besides that, the membranes exhibited the striking flexibility and mechanical properties. This study provided a green and facile method to inhibit magnetic nanoparticle aggregation without compromising the mechanical properties of the nanocomposites. Magnetically responsive BC membrane would have potential applications in electronic actuators, information storage, electromagnetic shielding coating and anti-counterfeit. - Highlights: ► Flexible magnetic film is prepared by in situ synthesis on bacterial cellulose. ► Ultrasound and PEG are used together to inhibit the nanoparticle aggregation. ► The magnetic membrane demonstrates the great superparamagnetic behavior

  11. Debranching of soluble wheat arabinoxylan dramatically enhances recalcitrant binding to cellulose

    DEFF Research Database (Denmark)

    Selig, Michael J.; Thygesen, Lisbeth G.; Felby, Claus

    2015-01-01

    The presence of xylan is a detriment to the enzymatic saccharification of cellulose in lignocelluloses. The inhibition of the processive cellobiohydrolase Cel7A by soluble wheat arabinoxylan is shown here to increase by 50 % following enzymatic treatment with a commercially-purified α-l-arabinofu......The presence of xylan is a detriment to the enzymatic saccharification of cellulose in lignocelluloses. The inhibition of the processive cellobiohydrolase Cel7A by soluble wheat arabinoxylan is shown here to increase by 50 % following enzymatic treatment with a commercially-purified α......-l-arabinofuranosidase. The enhanced inhibitory effect was shown by T2 relaxation time measurements via low field NMR to coincide with an increasing degree of constraint put on the water in xylan solutions. Furthermore, quartz crystal micro-balance with dissipation experiments showed that α-l-arabinofuranosidase treatment...

  12. Novel cellulose reinforcement for polymer electrolyte membranes with outstanding mechanical properties

    International Nuclear Information System (INIS)

    Nair, Jijeesh R.; Chiappone, A.; Gerbaldi, C.; Ijeri, Vijaykumar S.; Zeno, E.; Bongiovanni, R.; Bodoardo, S.; Penazzi, N.

    2011-01-01

    Highlights: ► UV-cured methacrylic-based composite gel-polymer electrolyte membranes for rechargeable lithium batteries. ► Excellent mechanical stability by reinforcement with classical cellulose handsheets. ► Fast and environmentally friendly preparation process, green and low cost cellulose reinforcement. ► Good electrochemical behaviour, stable cyclability and long-term performances in real battery configuration. - Abstract: Methacrylic-based thermo-set gel-polymer electrolytes obtained by an easy and reliable free radical photo-polymerisation process demonstrate good behaviour in terms of ionic conductivity, interfacial stability with the Li-metal electrode and cyclability in lithium cells. Though the obtained membranes are flexible, self standing and easy to handle, there is room for improving mechanical strength. In this respect, a novel approach is adopted in this work, in which a cellulose hand-sheet (paper), specifically designed for the specific application, is used as a composite reinforcing agent. To enhance its compatibility with the polymer matrix, cellulose is modified by UV-grafting of poly(ethylene glycol) methyl ether methacrylate on it. Excellent mechanical properties are obtained and good overall electrochemical performances are maintained; highlighting that such specific approach would make these hybrid organic, green, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible Li-based power sources.

  13. Chemical Functionalization and Characterization of Cellulose Extracted from Wheat Straw Using Acid Hydrolysis Methodologies

    Directory of Open Access Journals (Sweden)

    Chemar J. Huntley

    2015-01-01

    Full Text Available The nonuniform distribution of cellulose into many composite materials is attributed to the hydrogen bonding observed by the three hydroxyl groups located on each glucose monomer. As an alternative, chemical functionalization is performed to disrupt the strong hydrogen bonding behavior without significant altering of the chemical structure or lowering of the thermal stability. In this report, we use wheat straw as the biomass source for the extraction of cellulose and, subsequently, chemical modification via the Albright-Goldman and Jones oxidation reactions. X-ray diffraction analyses reveal that upon oxidation a slight change in the cellulose polymorphic structure (CI to CII can be observed when compared to its unmodified counterpart. Scanning electron microscopy analyses show that the oxidized cellulose structure exhibits fiber-like crystals with lengths and diameters on the micrometer scale. Thermal analyses (differential scanning calorimetry and thermogravimetric analysis show an increase in the thermal stability for the modified cellulose at extremely high temperatures (>300°C.

  14. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  15. Bacterial populations and environmental factors controlling cellulose degradation in an acidic Sphagnum peat.

    Science.gov (United States)

    Pankratov, Timofey A; Ivanova, Anastasia O; Dedysh, Svetlana N; Liesack, Werner

    2011-07-01

    Northern peatlands represent a major global carbon store harbouring approximately one-third of the global reserves of soil organic carbon. A large proportion of these peatlands consists of acidic Sphagnum-dominated ombrotrophic bogs, which are characterized by extremely low rates of plant debris decomposition. The degradation of cellulose, the major component of Sphagnum-derived litter, was monitored in long-term incubation experiments with acidic (pH 4.0) peat extracts. This process was almost undetectable at 10°C and occurred at low rates at 20°C, while it was significantly accelerated at both temperature regimes by the addition of available nitrogen. Cellulose breakdown was only partially inhibited in the presence of cycloheximide, suggesting that bacteria participated in this process. We aimed to identify these bacteria by a combination of molecular and cultivation approaches and to determine the factors that limit their activity in situ. The indigenous bacterial community in peat was dominated by Alphaproteobacteria and Acidobacteria. The addition of cellulose induced a clear shift in the community structure towards an increase in the relative abundance of the Bacteroidetes. Increasing temperature and nitrogen availability resulted in a selective development of bacteria phylogenetically related to Cytophaga hutchinsonii (94-95% 16S rRNA gene sequence similarity), which densely colonized microfibrils of cellulose. Among isolates obtained from this community only some subdivision 1 Acidobacteria were capable of degrading cellulose, albeit at a very slow rate. These Acidobacteria represent indigenous cellulolytic members of the microbial community in acidic peat and are easily out-competed by Cytophaga-like bacteria under conditions of increased nitrogen availability. Members of the phylum Firmicutes, known to be key players in cellulose degradation in neutral habitats, were not detected in the cellulolytic community enriched at low pH. © 2011 Society for

  16. All-cellulose composites of regenerated cellulose fibres by surface selective dissolution

    NARCIS (Netherlands)

    Soykeabkaew, N.; Nishino, T.; Peijs, Ton

    2009-01-01

    All-cellulose composites of Lyocell and high modulus/strength cellulose fibres were successfully prepared using a surface selective dissolution method. The effect of immersion time of the fibres in the solvent during composite's preparation and the effect of the starting fibre's structure on their

  17. Properties of cellulose derivatives produced from radiation-Modified cellulose pulps

    International Nuclear Information System (INIS)

    Iller, Edward; Stupinska, Halina; Starostka, Pawel

    2007-01-01

    The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared

  18. Effects of Crystal Orientation on Cellulose Nanocrystals−Cellulose Acetate Nanocomposite Fibers Prepared by Dry Spinning

    Science.gov (United States)

    Si Chen; Greg Schueneman; R. Byron Pipes; Jeffrey Youngblood; Robert J. Moon

    2014-01-01

    This work presents the development of dry spun cellulose acetate (CA) fibers using cellulose nanocrystals (CNCs) as reinforcements. Increasing amounts of CNCs were dispersed into CA fibers in efforts to improve the tensile strength and elastic modulus of the fiber. A systematic characterization of dispersion of CNCs in the polymer fiber and their effect on the...

  19. Preparation of cellulose II and IIII films by allomorphic conversion of bacterial cellulose I pellicles

    International Nuclear Information System (INIS)

    Faria-Tischer, Paula C.S.; Tischer, Cesar A.; Heux, Laurent; Le Denmat, Simon; Picart, Catherine; Sierakowski, Maria-R.

    2015-01-01

    The structural changes resulting from the conversion of native cellulose I (Cel I) into allomorphs II (Cel II) and III I (Cel III I ) have usually been studied using powder samples from plant or algal cellulose. In this work, the conversion of Cel I into Cel II and Cel III I was performed on bacterial cellulose films without any mechanical disruption. The surface texture of the films was observed by atomic force microscopy (AFM) and the morphology of the constituting cellulose ribbons, by transmission electron microscopy (TEM). The structural changes were characterized using solid-state NMR spectroscopy as well as X-ray and electron diffraction. The allomorphic change into Cel II and Cel III I resulted in films with different crystallinity, roughness and hydrophobic/hydrophilicity surface and the films remained intact during all process of allomorphic conversion. - Highlights: • Description of a method to modify the allomorphic structure of bacterial cellulose films • Preparation of films with specific morphologies and hydrophobic/hydrophilic surface characters • First report on cellulose III films from bacterial cellulose under swelling conditions • Detailed characterization of cellulose II and III films with complementary techniques • Development of films with specific properties as potential support for cells, enzymes, and drugs

  20. Degradation of γ-irradiated cellulose by the accumulating culture of a cellulose bacterium

    International Nuclear Information System (INIS)

    Namsaraev, B.B.; Kuznetsova, E.A.; Termkhitarova, N.G.

    1987-01-01

    Possibility of degradation of γ-irradiated cellulose by the accumulating culture of an anaerobic cellulose bacterium has been investigated. Cellulose irradiation by γ-quanta (Co 60 ) has been carried out using the RKh-30 device with 35.9 Gy/min dose rate. Radiation monitoring has been carried out by the standard ferrosulfate method. Samples have been irradiated in dry state or when water presenting with MGy. It is detected that the accumulating culture with the growth on the irradiated cellulose has a lag-phase, which duration reduces when the cellulose cleaning by flushing with distillation water. The culture has higher growth and substrate consumption rate when growing by cellulose irradiated in comparison with non-irradiated one. The economical coefficient is the same in using both the irradiated and non-irradiated cellulose. The quantity of forming reducing saccharides, organic acids, methane and carbon dioxide is the same both when cultivating by irradiated cellulose and by non-irradiated. pH of the culture liquid is shifted to the acid nature in the process of growth

  1. Reinforcement Effects from Nanodiamond in Cellulose Nanofibril Films.

    Science.gov (United States)

    Morimune-Moriya, Seira; Salajkova, Michaela; Zhou, Qi; Nishino, Takashi; Berglund, Lars A

    2018-04-05

    Although research on nanopaper structures from cellulose nanofibrils (CNF) is well established, the mechanical behavior is not well understood, especially not when CNF is combined with hard nanoparticles. Cationic CNF (Q-CNF) was prepared and successfully decorated by anionic nanodiamond (ND) nanoparticles in hydrocolloidal form. The Q-CNF/ND nanocomposites were filtered from a hydrocolloid and dried. Unlike many other carbon nanocomposites, the Q-CNF/ND nanocomposites were optically transparent. Reinforcement effects from the nanodiamond were remarkable, such as Young's modulus (9.8 GPa → 16.6 GPa) and tensile strength (209.5 MPa → 277.5 MPa) at a content of only 1.9% v/v of ND, and the reinforcement mechanisms are discussed. Strong effects on CNF network deformation mechanisms were revealed by loading-unloading experiments. Scratch hardness also increased strongly with increased addition of ND.

  2. Kinetic modeling and dynamic analysis of simultaneous saccharification and fermentation of cellulose to bioethanol

    International Nuclear Information System (INIS)

    Shadbahr, Jalil; Khan, Faisal; Zhang, Yan

    2017-01-01

    Highlights: • Deeper understanding of saccharification and fermentation process. • A new kinetic model for dynamic analysis of the simultaneous saccharification and fermentation. • Testing and validation of kinetic model. - Abstract: Kinetic modeling and dynamic analysis of the simultaneous saccharification and fermentation (SSF) of cellulose to ethanol was carried out in this study to determine the key reaction kinetics parameters and product inhibition features of the process. To obtain the more reliable kinetic parameters which can be applied for a wide range of operating conditions, batch SSF experiments were carried out at three enzyme loadings (10, 15 and 20 FPU/g cellulose) and two levels of initial concentrations of fermentable sugars (glucose and mannose). Results indicated that the maximum ethanol yield and concentration were achieved at high level of sugar concentrations with intermediate enzyme loading (15 FPU/g cellulose). Dynamic analysis of the acquired experimental results revealed that cellulase inhibition by cellobiose plays the most important role at high level of enzyme loading and low level of initial sugar concentrations. The inhibition of glucose becomes significant when high concentrations of sugars were present in the feedstock. Experimental results of SSF process also reveal that an efficient mixing between the phases helps to improve the ethanol yield significantly.

  3. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui [Chonnam National University, Bio-Energy Research Institute, Gwangju (Korea, Republic of)

    2010-10-15

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

  4. Cellulose Anionic Hydrogels Based on Cellulose Nanofibers As Natural Stimulants for Seed Germination and Seedling Growth.

    Science.gov (United States)

    Zhang, Hao; Yang, Minmin; Luan, Qian; Tang, Hu; Huang, Fenghong; Xiang, Xia; Yang, Chen; Bao, Yuping

    2017-05-17

    Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.

  5. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    International Nuclear Information System (INIS)

    Bae, Hyun Jong; Wi, Seung Gon; Kim, Su Bae; Shin, You Jung; Yi, Ju Hui

    2010-10-01

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. Research scope includes 1) screening of various microorganisms from decayed biomass in order to search for more efficient lignocellulose degrading microorganism, 2) identification and verification of new cell wall degrading cellulase for application cellulose bioconversion process, and 3) identification and characterization of novel genes involved in cellulose degradation. To find good microorganism candidates for lignocellulose degrading, 75 decayed samples from different areas were assayed in triplicate and analyzed. For cloning new cell wall degrading enzymes, we selected microorganisms because it have very good lignocellulose degradation ability. From that microorganisms, we have apparently cloned a new cellulase genes (10 genes). We are applying the new cloned cellulase genes to characterize in lignocellulsoe degradation that are most important to cellulosic biofuels production

  6. Laser cleaning of particulates from paper: Comparison between sized ground wood cellulose and pure cellulose

    International Nuclear Information System (INIS)

    Arif, S.; Kautek, W.

    2013-01-01

    Visible laser cleaning of charcoal particulates from yellow acid mechanical ground wood cellulose paper was compared with that from bleached sulphite softwood cellulose paper. About one order of magnitude of fluence range is available for a cleaning dynamics between the cleaning threshold and the destruction threshold for two laser pulses. Wood cellulose paper exhibited a higher destruction threshold of the original paper than that of the contaminated specimen because of heat transfer from the hot or evaporating charcoal particulates. In contrast, the contaminated bleached cellulose paper exhibited a higher destruction threshold due to shading by the particulates. The graphite particles are not only detached thermo-mechanically, but also by evaporation or combustion. A cleaning effect was found also outside the illuminated areas due to lateral blasting. Infrared measurements revealed dehydration/dehydrogenation reactions and cross-links by ether bonds together with structural changes of the cellulose chain arrangement and the degree of crystallinity.

  7. Production of Cellulosic Polymers from Agricultural Wastes

    Directory of Open Access Journals (Sweden)

    A. U. Israel

    2008-01-01

    Full Text Available Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm (Elais guineensis, raffia, piassava, bamboo pulp, bamboo bark from raphia palm (Raphia hookeri, stem and cob of maize plant (Zea mays, fruit fiber from coconut fruit (Cocos nucifera, sawdusts from cotton tree (Cossypium hirsutum, pear wood (Manilkara obovata, stem of Southern gamba green (Andropogon tectorus, sugarcane baggase (Saccharium officinarum and plantain stem (Musa paradisiaca. They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate. The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform.

  8. Natural cellulose fiber as substrate for supercapacitor.

    Science.gov (United States)

    Gui, Zhe; Zhu, Hongli; Gillette, Eleanor; Han, Xiaogang; Rubloff, Gary W; Hu, Liangbing; Lee, Sang Bok

    2013-07-23

    Cellulose fibers with porous structure and electrolyte absorption properties are considered to be a good potential substrate for the deposition of energy material for energy storage devices. Unlike traditional substrates, such as gold or stainless steel, paper prepared from cellulose fibers in this study not only functions as a substrate with large surface area but also acts as an interior electrolyte reservoir, where electrolyte can be absorbed much in the cellulose fibers and is ready to diffuse into an energy storage material. We demonstrated the value of this internal electrolyte reservoir by comparing a series of hierarchical hybrid supercapacitor electrodes based on homemade cellulose paper or polyester textile integrated with carbon nanotubes (CNTs) by simple solution dip and electrodeposited with MnO2. Atomic layer deposition of Al2O3 onto the fiber surface was used to limit electrolyte absorption into the fibers for comparison. Configurations designed with different numbers of ion diffusion pathways were compared to show that cellulose fibers in paper can act as a good interior electrolyte reservoir and provide an effective pathway for ion transport facilitation. Further optimization using an additional CNT coating resulted in an electrode of paper/CNTs/MnO2/CNTs, which has dual ion diffusion and electron transfer pathways and demonstrated superior supercapacitive performance. This paper highlights the merits of the mesoporous cellulose fibers as substrates for supercapacitor electrodes, in which the water-swelling effect of the cellulose fibers can absorb electrolyte, and the mesoporous internal structure of the fibers can provide channels for ions to diffuse to the electrochemical energy storage materials.

  9. Effect of ionizing radiation on starch and cellulose

    International Nuclear Information System (INIS)

    Klenha, J.; Bockova, J.

    1973-09-01

    The investigation is reported of the effects of ionizing radiation both on macromolecular systems generally and on polysaccharides, starch and cellulose. Attention is focused on changes in the physical and physico-chemical properties of starch and cellulose, such as starch swelling, gelation, viscosity, solubility, reaction with iodine, UV, IR and ESR spectra, chemical changes resulting from radiolysis and from the effect of amylases on irradiated starch, changes in cellulose fibre strength, water absorption, stain affinity, and also the degradation of cellulose by radiation and the effect of cellulases on irradiated cellulose. Practical applications of the findings concerning cellulose degradation are discussed. (author)

  10. Experimental study on the liquefaction of cellulose in supercritical ethanol

    Science.gov (United States)

    Peng, Jinxing; Liu, Xinyuan; Bao, Zhenbo

    2018-03-01

    Cellulose is the major composition of solid waste for producing biofuel; cellulose liquefaction is helpful for realizing biomass supercritical liquefaction process. This paper is taking supercritical ethanol as the medium, liquefied cellulose with the intermittence installation of high press cauldron. Experiments have studied technical condition and the technology parameter of cellulose liquefaction in supercritical ethanol, and the pyrolysis mechanism was analysed based on the pyrolysis product. Results show that cellulose can be liquefied, can get good effect through appropriate technology condition. Under not catalyst, highest liquefaction rate of cellulose can reach 73.5%. The composition of the pyrolysis product was determined by GC-MS.

  11. Utilization of waste cellulose. III. Comparative study of the activity of the cellulases of trichoderma viride and Aspergillus niger towards different cellulosic substrates

    Energy Technology Data Exchange (ETDEWEB)

    David, C.; Thiry, P.

    1981-01-01

    The kinetics of the saccharification of filter paper-derived cellulose by cellulases of Aspergillus niger and Tricoderma viride were studied. The formation of glucose and of total reducing sugar was measured as a function of time for the hydrolysis of cellulose by the same quantity of filter paper units from T. viride and (or) A. niger. Long term efficiency was lower for A. niger but an important synergistic effect was observed for the mixture of the enzymes. This synergistic action was attributed to a better balance of endo- and exoglucananses and to the addition to T. viride of thermally stable endoglucanases from A. niger. The beta-glucosidases formed in large quantity by A. niger were thermally unstable and susceptible to product inhibition and did not play any role in the observed synergistic action.

  12. Dielectric barrier discharge plasma pretreatment on hydrolysis of microcrystalline cellulose

    Science.gov (United States)

    Huang, Fangmin; Long, Zhouyang; Liu, Sa; Qin, Zhenglong

    2017-04-01

    Dielectric barrier discharge (DBD) plasma was used as a pretreatment method for downstream hydrolysis of microcrystalline cellulose (MCC). The degree of polymerization (DP) of MCC decreased after it was pretreated by DBD plasma under a carrier gas of air/argon. The effectiveness of depolymerization was found to be influenced by the crystallinity of MCC when under the pretreatment of DBD plasma. With the addition of tert-butyl alcohol in the treated MCC water suspension solution, depolymerization effectiveness of MCC was inhibited. When MCC was pretreated by DBD plasma for 30 min, the total reducing sugar concentration (TRSC) and liquefaction yield (LY) of pretreated-MCC (PMCC) increased by 82.98% and 34.18% respectively compared with those for raw MCC.

  13. Isolation and Characterization of Two Cellulose Morphology Mutants of Gluconacetobacter hansenii ATCC23769 Producing Cellulose with Lower Crystallinity

    Science.gov (United States)

    Deng, Ying; Nagachar, Nivedita; Fang, Lin; Luan, Xin; Catchmark, Jeffrey M.; Tien, Ming; Kao, Teh-hui

    2015-01-01

    Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC). These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of peptidoglycan in the

  14. Isolation and characterization of two cellulose morphology mutants of Gluconacetobacter hansenii ATCC23769 producing cellulose with lower crystallinity.

    Directory of Open Access Journals (Sweden)

    Ying Deng

    Full Text Available Gluconacetobacter hansenii, a Gram-negative bacterium, produces and secrets highly crystalline cellulose into growth medium, and has long been used as a model system for studying cellulose synthesis in higher plants. Cellulose synthesis involves the formation of β-1,4 glucan chains via the polymerization of glucose units by a multi-enzyme cellulose synthase complex (CSC. These glucan chains assemble into ordered structures including crystalline microfibrils. AcsA is the catalytic subunit of the cellulose synthase enzymes in the CSC, and AcsC is required for the secretion of cellulose. However, little is known about other proteins required for the assembly of crystalline cellulose. To address this question, we visually examined cellulose pellicles formed in growth media of 763 individual colonies of G. hansenii generated via Tn5 transposon insertion mutagenesis, and identified 85 that produced cellulose with altered morphologies. X-ray diffraction analysis of these 85 mutants identified two that produced cellulose with significantly lower crystallinity than wild type. The gene disrupted in one of these two mutants encoded a lysine decarboxylase and that in the other encoded an alanine racemase. Solid-state NMR analysis revealed that cellulose produced by these two mutants contained increased amounts of non-crystalline cellulose and monosaccharides associated with non-cellulosic polysaccharides as compared to the wild type. Monosaccharide analysis detected higher percentages of galactose and mannose in cellulose produced by both mutants. Field emission scanning electron microscopy showed that cellulose produced by the mutants was unevenly distributed, with some regions appearing to contain deposition of non-cellulosic polysaccharides; however, the width of the ribbon was comparable to that of normal cellulose. As both lysine decarboxylase and alanine racemase are required for the integrity of peptidoglycan, we propose a model for the role of

  15. Infidelity in the outback: climate signal recorded in Δ18O of leaf but not branch cellulose of eucalypts across an Australian aridity gradient.

    Science.gov (United States)

    Cheesman, Alexander W; Cernusak, Lucas A

    2017-05-01

    The isotopic composition of leaf water in terrestrial plants is highly dependent upon a plant's environment. This isotopic signature can become integrated into organic molecules, allowing the isotopic composition of biomarkers such as cellulose to be used as sensitive paleo and climatic proxies. However, the mechanisms by which cellulose isotopic composition reflect environmental conditions are complex, and may vary between leaf and woody tissues. To date few empirical tests have been made on the relative roles of leaf-water enrichment and source water on the isotopic composition of leaf and wood cellulose within the same plant. Here, we study both leaf and branch wood cellulose, as well as xylem/source water of eucalypts across a 900 km aridity gradient in NE Australia. Across 11 sites, spanning average annual precipitation of 235-1400 mm and average relative humidity of 33-70%, we found a strong and consistent trend in leaf cellulose. However, once the effect of altered source water was considered we found wood cellulose to show no trend across this environmental gradient. We consider potential mechanisms that could explain the 'damping' of a climatic signal within wood cellulose and consider the implication and limitations on the use of tree-ring cellulose as a climate proxy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Natural cellulose ionogels for soft artificial muscles.

    Science.gov (United States)

    Nevstrueva, Daria; Murashko, Kirill; Vunder, Veiko; Aabloo, Alvo; Pihlajamäki, Arto; Mänttäri, Mika; Pyrhönen, Juha; Koiranen, Tuomas; Torop, Janno

    2018-01-01

    Rapid development of soft micromanipulation techniques for human friendly electronics has raised the demand for the devices to be able to carry out mechanical work on a micro- and macroscale. The natural cellulose-based ionogels (CEL-iGEL) hold a great potential for soft artificial muscle application, due to its flexibility, low driving voltage and biocompatibility. The CEL-iGEL composites undergo reversible bending already at ±500mV step-voltage values. A fast response to the voltage applied and high ionic conductivity of membranous actuator is achieved by a complete dissolution of cellulose in 1-ethyl-3-methylimidazolium acetate [EMIm][OAc]. The CEL-iGEL supported cellulose actuator films were cast out of cellulose-[EMIm][OAc] solution via phase inversion in H 2 O. The facile preparation method ensured uniform morphology along the layers and stand for the high ionic-liquid loading in a porous cellulose scaffold. During the electromechanical characterization, the CEL-iGEL actuators showed exponential dependence to the voltage applied with the max strain difference values reaching up to 0.6% at 2 V. Electrochemical analysis confirmed the good stability of CEL-iGEL actuators and determined the safe working voltage value to be below 2.5V. To predict and estimate the deformation for various step input voltages, a mathematical model was proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Cellulose multilayer Membranes manufacture with Ionic liquid

    KAUST Repository

    Livazovic, Sara

    2015-05-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. By these methods porous supports could be easily coated with semi-crystalline cellulose. The membranes were hydrophilic with contact angles as low as 22.0°, molecular weight cut-off as low as 3000 g mol-1 with corresponding water permeance of 13.8 Lm−2 h−1 bar−1. Self-standing cellulose membranes were also manufactured without porous substrate, using only ionic liquid as green solvent. This membrane was insoluble in water, tetrahydrofuran, hexane, N,N-dimethylformamide, 1-methyl-2-pyrrolidinone and N,N-dimethylacetamide.

  18. Isotopic composition of cellulose from aquatic organisms

    International Nuclear Information System (INIS)

    DeNiro, M.J.; Epstein, S.

    1981-01-01

    The stable isotopic ratios of oxygen, carbon and the non-exchangeable carbon-bound hydrogen of cellulose from marine plants and animals collected in their natural habitats and from freshwater vascular plants grown in the laboratory under controlled conditions were determined. The delta 18 O values of cellulose from all the plants and animals were 27 +- 3 parts per thousand more positive than the delta 18 O values of the waters in which the organisms grew. Temperature had little or no influence on this relationship for three species of freshwater vascular plants that were analyzed. The deltaD values of the non-exchangeable hydrogen of cellulose from different organisms that grew in the same environment differed by large amounts. This difference ranged up to 200 parts per thousand for different species of algae collected at a single site; the corresponding difference for different species of tunicates and vascular plants was 60 and 20 parts per thousand respectively. The deltaD values of cellulose nitrate from different species of freshwater vascular plants grown in water of constant temperature and isotopic composition differed by as much as 60 parts per thousand. The relationship between the deltaD values of the carbon-bound hydrogen of cellulose and the water used in its synthesis displayed a significant temperature dependence for four species of freshwater vascular plants that were analyzed. (author)

  19. Enzymatic hydrolysis of pretreated cellulosic wastes by the cellulase complex of Myceliophthora thermophila D-14 to produce ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Roy, S K; Sadhukhan, R; Raha, S K; Chakrabarty, S L [Bose Institute, Calcutta (India). Dept. of Microbiology

    1991-06-01

    Pretreatment of different cellulosic wastes and their subsequent saccharification by thermostable cellulase from a thermophilic fungus Myceliophthora thermophila D-14 was investigated. Alkali treatment was found to be most effective. Carboxymethyl cellulose and untreated materials were used as controls. Significant inhibition of the cellulase activity was observed in the presence of glucose, but with ethanol no such effect was detected. The conversion of sugar to ethanol varied from 21-50% depending on the nature of substrate used. 14 refs., 2 figs., 4 tabs.

  20. Modified cellulose synthase gene from 'Arabidopsis thaliana' confers herbicide resistance to plants

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, Chris R.; Scieble, Wolf

    2000-10-11

    Cellulose synthase ('CS'), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl) phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  1. Cellulose degradation: a therapeutic strategy in the improved treatment of Acanthamoeba infections.

    Science.gov (United States)

    Lakhundi, Sahreena; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2015-01-14

    Acanthamoeba is an opportunistic free-living amoeba that can cause blinding keratitis and fatal brain infection. Early diagnosis, followed by aggressive treatment is a pre-requisite in the successful treatment but even then the prognosis remains poor. A major drawback during the course of treatment is the ability of the amoeba to enclose itself within a shell (a process known as encystment), making it resistant to chemotherapeutic agents. As the cyst wall is partly made of cellulose, thus cellulose degradation offers a potential therapeutic strategy in the effective targeting of trophozoite encased within the cyst walls. Here, we present a comprehensive report on the structure of cellulose and cellulases, as well as known cellulose degradation mechanisms with an eye to target the Acanthamoeba cyst wall. The disruption of the cyst wall will make amoeba (concealed within) susceptible to chemotherapeutic agents, and at the very least inhibition of the excystment process will impede infection recurrence, as we bring these promising drug targets into focus so that they can be explored to their fullest.

  2. High Dehumidification Performance of Amorphous Cellulose Composite Membranes prepared from Trimethylsilyl Cellulose

    KAUST Repository

    Puspasari, Tiara

    2018-04-11

    Cellulose is widely regarded as an environmentally friendly, natural and low cost material which can significantly contribute the sustainable economic growth. In this study, cellulose composite membranes were prepared via regeneration of trimethylsilyl cellulose (TMSC), an easily synthesized cellulose derivative. The amorphous hydrophilic feature of the regenerated cellulose enabled fast permeation of water vapour. The pore-free cellulose layer thickness was adjustable by the initial TMSC concentration and acted as an efficient gas barrier. As a result, a 5,000 GPU water vapour transmission rate (WVTR) at the highest ideal selectivity of 1.1 x 106 was achieved by the membranes spin coated from a 7% (w/w) TMSC solution. The membranes maintained a 4,000 GPU WVTR with selectivity of 1.1 x 104 in the mixed-gas experiments, surpassing the performances of the previously reported composite membranes. This study provides a simple way to not only produce high performance membranes but also to advance cellulose as a low-cost and sustainable membrane material for dehumidification applications.

  3. A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods.

    Science.gov (United States)

    Du, Lanxing; Wang, Jinwu; Zhang, Yang; Qi, Chusheng; Wolcott, Michael P; Yu, Zhiming

    2017-08-01

    This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80min or 120min (BMW 80 , BMW 120 ) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW 120 was achieved, which was three times as high as the conversion of BMW 80 . The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72g/L and 88.16g/L lignosulfonate concentration, respectively, were harvested from HR 80 and HR 120 , and 42.6±0.5% lignin were removed. The subsequent solid residuals were purified to produce cellulose and then this material was acid-hydrolyzed to produce cellulose nanocrystals. The BMW 120 maintained smaller particle size and aspect ratio during each step of during the multiple processes, while the average aspect ratio of its cellulose nanocrystals was larger. The crystallinity of both materials increased with each step of wet processing, reaching to 74% for the cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Extraction and characterization of natural cellulose fibers from maize tassel

    CSIR Research Space (South Africa)

    Maepa, CE

    2015-04-01

    Full Text Available This article reports on the extraction and characterization of novel natural cellulose fibers obtained from the maize (tassel) plant. Cellulose was extracted from the agricultural residue (waste biomaterial) of maize tassel. The maize tassel fibers...

  5. Mechanical properties of cellulose nanomaterials studied by contact resonance atomic force microscopy

    Science.gov (United States)

    Ryan Wagner; Robert J. Moon; Arvind Raman

    2016-01-01

    Quantification of the mechanical properties of cellulose nanomaterials is key to the development of new cellulose nanomaterial based products. Using contact resonance atomic force microscopy we measured and mapped the transverse elastic modulus of three types of cellulosic nanoparticles: tunicate cellulose nanocrystals, wood cellulose nanocrystals, and wood cellulose...

  6. Inhibition of cellulase-catalyzed lignocellulosic hydrolysis by iron and oxidative metal ions and complexes.

    Science.gov (United States)

    Tejirian, Ani; Xu, Feng

    2010-12-01

    Enzymatic lignocellulose hydrolysis plays a key role in microbially driven carbon cycling and energy conversion and holds promise for bio-based energy and chemical industries. Cellulases (key lignocellulose-active enzymes) are prone to interference from various noncellulosic substances (e.g., metal ions). During natural cellulolysis, these substances may arise from other microbial activities or abiotic events, and during industrial cellulolysis, they may be derived from biomass feedstocks or upstream treatments. Knowledge about cellulolysis-inhibiting reactions is of importance for the microbiology of natural biomass degradation and the development of biomass conversion technology. Different metal ions, including those native to microbial activity or employed for biomass pretreatments, are often tested for enzymatic cellulolysis. Only a few metal ions act as inhibitors of cellulases, which include ferrous and ferric ions as well as cupric ion. In this study, we showed inhibition by ferrous/ferric ions as part of a more general effect from oxidative (or redox-active) metal ions and their complexes. The correlation between inhibition and oxidation potential indicated the oxidative nature of the inhibition, and the dependence on air established the catalytic role that iron ions played in mediating the dioxygen inhibition of cellulolysis. Individual cellulases showed different susceptibilities to inhibition. It is likely that the inhibition exerted its effect more on cellulose than on cellulase. Strong iron ion chelators and polyethylene glycols could mitigate the inhibition. Potential microbiological and industrial implications of the observed effect of redox-active metal ions on enzymatic cellulolysis, as well as the prevention and mitigation of this effect in industrial biomass conversion, are discussed.

  7. Radiation-induced transformations of cellulose ethers

    International Nuclear Information System (INIS)

    Nud'ga, L.A.; Petropavlovskii, G.S.; Plisko, E.A.; Isakova, O.V.; Ershov, B.G.

    1988-01-01

    The purpose of this investigation was to study the transformation which take place under the action of γ-radiation in a number of cellulose ethers containing both saturated (carboxymethyl, hydroxyethyl) and unsaturated (allyl, methacryloyl) groups. Irradiation was carried out on a 60 Co unit in air at 77 and 300 K; the dose rate was 37 and 50 kGy/h respectively. The EPR spectra of γ-irradiated hydroxyethyl- and allylhydroxyethylcelluloses are identical. Under the action of γ-radiation extensive changes took place in cellulose ethers which are exhibited in degradation or the formation of three-dimensional structures and are accompanied by a change in the functional composition. The efficiency in the formation of radicals and their localization are determined by the nature and number of substituents in the cellulose ethers

  8. African perspective on cellulosic ethanol production

    DEFF Research Database (Denmark)

    Bensah, Edem Cudjoe; Kemausuor, Francis; Miezah, Kodwo

    2015-01-01

    A major challenge to commercial production of cellulosic ethanol pertains to the cost-effective breakdown of the complex and recalcitrant structure of lignocellulose into its components via pretreatment, the cost of enzymes for hydrolysis and fermentation, and the conversion rate of C5 sugars...... to ethanol, among others. While the industrialized and some emerging countries are gradually breaking grounds in cellulosic ethanol, most African countries have made little effort in research and development even though the continent is rich in lignocellulosic biomass. The paper estimates residues from...... widely available crops and municipal waste and determines their respective theoretical ethanol potential (around 22 billion litres annually). It further reviews stages involved in the production of cellulosic ethanol, focussing on processing methods that can be adapted to current situation in most...

  9. ADSORPTION AND RELEASING PROPERTIES OF BEAD CELLULOSE

    Institute of Scientific and Technical Information of China (English)

    A. Morales; E. Bordallo; V. Leon; J. Rieumont

    2004-01-01

    The adsorption of some dyes on samples of bead cellulose obtained in the Unit of Research-Production "Cuba 9"was studied. Methylene blue, alizarin red and congo red fitted the adsorption isotherm of Langmuir. Adsorption kinetics at pH = 6 was linear with the square root of time indicating the diffusion is the controlling step. At pH = 12 a non-Fickian trend was observed and adsorption was higher for the first two dyes. Experiments carried out to release the methylene blue occluded in the cellulose beads gave a kinetic behavior of zero order. The study of cytochrome C adsorption was included to test a proteinic material. Crosslinking of bead cellulose was performed with epichlorohydrin decreasing its adsorption capacity in acidic or alkaline solution.

  10. Sulfated cellulose thin films with antithrombin affinity

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  11. Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis II. Quantification of inhibition and suitability of membrane reactors

    DEFF Research Database (Denmark)

    Andric, Pavle; Meyer, Anne S.; Jensen, Peter Arendt

    2010-01-01

    conversion are required for alleviation of glucose product inhibition. Supported by numerous calculations this review assesses the quantitative aspects of glucose product inhibition on enzyme-catalyzed cellulose degradation rates. The significance of glucose product inhibition on dimensioning of different......Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose...... reactor features, including system set-up, dilution rate, glucose output profile, and the problem of cellobiose are examined to illustrate the quantitative significance of the glucose product inhibition and the total glucose concentration on the cellulolytic conversion rate. Comprehensive overviews...

  12. Bioinspired lubricating films of cellulose nanofibrils and hyaluronic acid.

    Science.gov (United States)

    Valle-Delgado, Juan José; Johansson, Leena-Sisko; Österberg, Monika

    2016-02-01

    The development of materials that combine the excellent mechanical strength of cellulose nanofibrils (CNF) with the lubricating properties of hyaluronic acid (HA) is a new, promising approach to cartilage implants not explored so far. A simple, solvent-free method to produce a very lubricating, strong cellulosic material by covalently attaching HA to the surface of CNF films is described in this work. A detailed analysis of the tribological properties of the CNF films with and without HA is also presented. Surface and friction forces at micro/nanoscale between model hard surfaces (glass microspheres) and the CNF thin films were measured using an atomic force microscope and the colloid probe technique. The effect of HA attachment, the pH and the ionic strength of the aqueous medium on the forces was examined. Excellent lubrication was observed for CNF films with HA attached in conditions where the HA layer was highly hydrated. These results pave the way for the development of new nanocellulose-based materials with good lubrication properties that could be used in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally...

  14. Strong Langmuir turbulence

    International Nuclear Information System (INIS)

    Goldman, M.V.

    1984-01-01

    After a brief discussion of beam-excited Langmuir turbulence in the solar wind, we explain the criteria for wave-particle, three-wave and strong turbulence interactions. We then present the results of a numerical integration of the Zakharov equations, which describe the strong turbulence saturation of a weak (low-density) high energy, bump-on-tail beam instability. (author)

  15. Microfibrillated cellulose and new nanocomposite materials: a review

    DEFF Research Database (Denmark)

    Siró, Istvan; Plackett, David

    2010-01-01

    Due to their abundance, high strength and stiffness, low weight and biodegradability, nano-scale cellulose fiber materials (e.g., microfibrillated cellulose and bacterial cellulose) serve as promising candidates for bio-nanocomposite production. Such new high-value materials are the subject...... in order to address this hurdle. This review summarizes progress in nanocellulose preparation with a particular focus on microfibrillated cellulose and also discusses recent developments in bio-nanocomposite fabrication based on nanocellulose....

  16. Paper Actuators Made with Cellulose and Hybrid Materials

    OpenAIRE

    Kim, Jaehwan; Yun, Sungryul; Mahadeva, Suresha K.; Yun, Kiju; Yang, Sang Yeol; Maniruzzaman, Mohammad

    2010-01-01

    Recently, cellulose has been re-discovered as a smart material that can be used as sensor and actuator materials, which is termed electro-active paper (EAPap). This paper reports recent advances in paper actuators made with cellulose and hybrid materials such as multi-walled carbon nanotubes, conducting polymers and ionic liquids. Two distinct actuator principles in EAPap actuators are demonstrated: piezoelectric effect and ion migration effect in cellulose. Piezoelectricity of cellulose EAPa...

  17. Effect of γ-radiation on the saccharification of cellulose

    International Nuclear Information System (INIS)

    De la Rosa, A.M.; Banzon, R.B.; Abad, L.V.; Nuguid, Z.F.; Bulos, A.S.

    1985-01-01

    The effect of gamma radiation on the acid and saccharification of agricultural cellulosic wastes was investigated. Radiation doses of 200 KGy and higher significantly increased the saccharification of rice straw, rice hull and corn husk. The observed radiation effects varied with the cellulosic material. Rice straw exhibited the greatest radiosensitivity while rice hull showed the least susceptibility to gamma radiation. Possible mechanisms for the radiation-induced degradation of cellulose and agricultural cellulosic wastes are discussed. (author)

  18. 21 CFR 172.872 - Methyl ethyl cellulose.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methyl ethyl cellulose. 172.872 Section 172.872... CONSUMPTION Multipurpose Additives § 172.872 Methyl ethyl cellulose. The food additive methyl ethyl cellulose... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number...

  19. Cellulose accessibility limits the effectiveness of minimum cellulase loading on the efficient hydrolysis of pretreated lignocellulosic substrates

    Directory of Open Access Journals (Sweden)

    Saddler Jack N

    2011-02-01

    Full Text Available Abstract A range of lignocellulosic feedstocks (including agricultural, softwood and hardwood substrates were pretreated with either sulfur dioxide-catalyzed steam or an ethanol organosolv procedure to try to establish a reliable assessment of the factors governing the minimum protein loading that could be used to achieve efficient hydrolysis. A statistical design approach was first used to define what might constitute the minimum protein loading (cellulases and β-glucosidase that could be used to achieve efficient saccharification (defined as at least 70% glucan conversion of the pretreated substrates after 72 hours of hydrolysis. The likely substrate factors that limit cellulose availability/accessibility were assessed, and then compared with the optimized minimum amounts of protein used to obtain effective hydrolysis. The optimized minimum protein loadings to achieve efficient hydrolysis of seven pretreated substrates ranged between 18 and 63 mg protein per gram of glucan. Within the similarly pretreated group of lignocellulosic feedstocks, the agricultural residues (corn stover and corn fiber required significantly lower protein loadings to achieve efficient hydrolysis than did the pretreated woody biomass (poplar, douglas fir and lodgepole pine. Regardless of the substantial differences in the source, structure and chemical composition of the feedstocks, and the difference in the pretreatment technology used, the protein loading required to achieve efficient hydrolysis of lignocellulosic substrates was strongly dependent on the accessibility of the cellulosic component of each of the substrates. We found that cellulose-rich substrates with highly accessible cellulose, as assessed by the Simons' stain method, required a lower protein loading per gram of glucan to obtain efficient hydrolysis compared with substrates containing less accessible cellulose. These results suggest that the rate-limiting step during hydrolysis is not the catalytic

  20. Electrospinning cellulose based nanofibers for sensor applications

    Science.gov (United States)

    Nartker, Steven

    2009-12-01

    Bacterial pathogens have recently become a serious threat to the food and water supply. A biosensor based on an electrochemical immunoassay has been developed for detecting food borne pathogens, such as Escherichia coli (E. coli) O157:H7. These sensors consist of several materials including, cellulose, cellulose nitrate, polyaniline and glass fibers. The current sensors have not been optimized in terms of microscale architecture and materials. The major problem associated with the current sensors is the limited concentration range of pathogens that provides a linear response on the concentration conductivity chart. Electrospinning is a process that can be used to create a patterned fiber mat design that will increase the linear range and lower the detection limit of these sensors by improving the microscale architecture. Using the electrospinning process to produce novel mats of cellulose nitrate will offer improved surface area, and the cellulose nitrate can be treated to further improve chemical interactions required for sensor activity. The macro and micro architecture of the sensor is critical to the performance of the sensors. Electrospinning technology can be used to create patterned architectures of nanofibers that will enhance sensor performance. To date electrospinning of cellulose nitrate has not been performed and optimization of the electrospinning process will provide novel materials suitable for applications such as filtration and sensing. The goal of this research is to identify and elucidate the primary materials and process factors necessary to produce cellulose nitrate nanofibers using the electrospinning process that will improve the performance of biosensors. Cellulose nitrate is readily dissolved in common organic solvents such as acetone, tetrahydrofuran (THF) and N,N dimethylformamide (DMF). These solvents can be mixed with other latent solvents such as ethanol and other alcohols to provide a solvent system with good electrospinning behavior

  1. Accumulation of noncrystalline cellulose in Physarum microplasmodia

    OpenAIRE

    Ogawa, Kyoko; Maki, Hisae; Sato, Mamiko; Ashihara, Hiroshi; Kaneko, Takako S.

    2013-01-01

    Physarum plasmodium lives as a slimy mass of protoplast in the dark fragments into small multinucleated microplasmodia (mPL) in a liquid medium. When mPL are exposed to several unfavorable environments, they transform into ?spherules? with a cell wall. Using a synchronous spherule-induction system for mPL, we examined the effect of 2,6-dichlorobenzonitrile on the synthesis of cellulose in mPL, by observing mPL under a fluorescence microscope, and isolated cellulose from mPL to identify them m...

  2. New thermophilic anaerobes that decompose crystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Taya, M; Hinoki, H; Suzuki, Y; Yagi, T; Yap, M G.S.; Kobayashi, T

    1985-01-01

    Two strains (designated as 25A and 3B) of cellulolytic, thermophilic, anaerobic, spore-forming bacteria were newly isolated from an alkaline hot spring through enrichment cultures at 60/sup 0/C. Though strain 25A was nearly identical to Clostridium thermocellum ATCC 27405 as a reference strain, strain 3B had some characteristics different from the reference; no flagellation, alkalophilic growth property (optimum pH of 7.5-8) and orange-colored pigmentation of the cell mass. Strain 3B effectively decomposed micro-crystalline cellulose (Avicel) and raw cellulosics (rice straw, newspaper, and bagasse) without physical or chemical pretreatments. 20 references, 2 figures, 2 tables.

  3. Cellulose nanocrystal: electronically conducting polymer nanocomposites for supercapacitors

    OpenAIRE

    Liew, Soon Yee

    2012-01-01

    This thesis describes the use of cellulose nanocrystals for the fabrication of porous nanocomposites with electronic conducting polymers for electrochemical supercapacitor applications. The exceptional strength and negatively charged surface functionalities on cellulose nanocrystals are utilised in these nanocomposites. The negatively charged surface functionalities on cellulose nanocrystals allow their simultaneous incorporation into electropolymerised, positively charged conducting polymer ...

  4. Nanotechnology : emerging applications of cellulose-based green magnetic nanocomposites

    Science.gov (United States)

    Tao Wang; Zhiyong Cai; Lei Liu; Ilker S. Bayer; Abhijit Biswas

    2010-01-01

    In recent years, a new type of nanocomposite – cellulose based hybrid nanocomposites, which adopts cellulose nanofibers as matrices, has been intensively developed. Among these materials, hybrid nanocomposites consisting of cellulosic fibers and magnetic nanoparticles have recently attracted much attention due to their potential novel applications in biomedicine,...

  5. Cyanobacterial cellulose synthesis in the light of the photanol concept

    NARCIS (Netherlands)

    Schuurmans, R.M.; Matthijs, H.C.P.; Stal, L.J.; Hellingwerf, K.J.; Sharma, N.K.; Rai, A.K.; Stal, L.J.

    2014-01-01

    The detailed knowledge already available about cellulose synthases and their regulation, plus emerging insights into the process of cellulose secretion in cyanobacteria make cellulose an attractive polymer for the application of the photanol concept in an economically viable production process. By

  6. Structural differences of xylans affect their interaction with cellulose

    NARCIS (Netherlands)

    Kabel, M.A.; Borne, van den H.; Vincken, J.P.; Voragen, A.G.J.; Schols, H.A.

    2007-01-01

    The affinity of xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different xylans to cellulose. Therefore, the adsorption of various xylans to

  7. Tritium transfer studies in cellulose-HTO system

    International Nuclear Information System (INIS)

    Jayaraman, A.P.; Misra, B.M.

    1986-01-01

    This paper describes some aspects of studies on transfer of tritium to cellulose from tritiated water at six different specific activities and discusses the generalized tritiation pattern. Cellulose was irradiated in steps to 10 M Rads and the tritium transfer was determined at each stage. Experimental results signify substantial increase of tritiation in cellulose at higher dose of irradiation. (author). 8 refs

  8. Surface chemistry of cellulose : from natural fibres to model surfaces

    NARCIS (Netherlands)

    Kontturi, E.J.

    2005-01-01

    The theme of the thesis was to link together the research aspects of cellulose occurring in nature (in natural wood fibres) and model surfaces of cellulose. Fundamental changes in cellulose (or fibre) during recycling of paper was a pragmatic aspect which was retained throughout the thesis with

  9. Formation of Irreversible H-bonds in Cellulose Materials

    Science.gov (United States)

    Umesh P. Agarwal; Sally A. Ralph; Rick S. Reiner; Nicole M. Stark

    2015-01-01

    Understanding of formation of irreversible Hbonds in cellulose is important in a number of fields. For example, fields as diverse as pulp and paper and enzymatic saccharification of cellulose are affected. In the present investigation, the phenomenon of formation of irreversible H-bonds is studied in a variety of celluloses and under two different drying conditions....

  10. RADIOCHEMICAL YIELDS OF GRAFT POLYMERIZATION REACTIONS OF CELLULOSE

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Jr, J C; Blouin, F A

    1963-12-15

    The preparation of radioinduced graft polymers of cotton cellulose, while retaining the fibrous nature and high molecular weight of the cellulose, depended primarily on the radiochemical yields of cellulose reactions and of graft polymerization reactions. Yields of the initial major molecular changes in cellulosic polymer indicated that, in the case of scission of the molecule and carboxyl group formation, chain reactions were not initiated by radiation; however, in the case of carbonyl group formation chain reactions were initiated but quickly terminated. Generally, experimental procedures, used in graft polymerization reactions, were: simultaneous irradiation reactions, that is, application of monomers or solutions of monomers to cellulose or chemically modified celluloses, then irradiation; and post-irradiation reactions, that is, irradiation of cellulose or chemically modified celluloses, then after removal from the field of radiation, contacting the irradiated cellulose with monomer. Some of the most important factors influencing the radiochemical yields of graft polymerization reactions, of styrene and acrylonitrile onto cellulose were: concentration of monomer in treating solution; solvent; ratio of monomer solution to cellulose; prior chemical modification of cellulose; and absence of oxygen, particularly in post-irradiation reactions. Experimental data are presented, and the direct and indirect effects of Co/sup 60/ gamma radiation on these reactions are discussed. (auth)

  11. Characterising the cellulose synthase complexes of cell walls

    NARCIS (Netherlands)

    Mansoori Zangir, N.

    2012-01-01

    One of the characteristics of the plant kingdom is the presence of a structural cell wall. Cellulose is a major component in both the primary and secondary cell walls of plants. In higher plants cellulose is synthesized by so called rosette protein complexes with cellulose synthases (CESAs) as

  12. 16 CFR 501.6 - Cellulose sponges, irregular dimensions.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Cellulose sponges, irregular dimensions. 501... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.6 Cellulose sponges, irregular dimensions. Variety packages of cellulose sponges of irregular dimensions, are exempted from the requirements of § 500.25 of this...

  13. Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: I. Significance and mechanism of cellobiose and glucose inhibition on cellulolytic enzymes

    DEFF Research Database (Denmark)

    Andric, Pavle; Meyer, Anne S.; Jensen, Peter Arendt

    2010-01-01

    Achievement of efficient enzymatic degradation of cellulose to glucose is one of the main prerequisites and one of the main challenges in the biological conversion of lignocellulosic biomass to liquid fuels and other valuable products. The specific inhibitory interferences by cellobiose and glucose...... on enzyme-catalyzed cellulose hydrolysis reactions impose significant limitations on the efficiency of lignocellulose conversion especially at high-biomass dry matter conditions. To provide the base for selecting the optimal reactor conditions, this paper reviews the reaction kinetics, mechanisms......, and significance of this product inhibition, notably the cellobiose and glucose inhibition, on enzymatic cellulose hydrolysis. Particular emphasis is put on the distinct complexity of cellulose as a substrate, the multi-enzymatic nature of the cellulolytic degradation, and the particular features of cellulase...

  14. Cellulose ionics: switching ionic diode responses by surface charge in reconstituted cellulose films.

    Science.gov (United States)

    Aaronson, Barak D B; Wigmore, David; Johns, Marcus A; Scott, Janet L; Polikarpov, Igor; Marken, Frank

    2017-09-25

    Cellulose films as well as chitosan-modified cellulose films of approximately 5 μm thickness, reconstituted from ionic liquid media onto a poly(ethylene-terephthalate) (PET, 6 μm thickness) film with a 5, 10, 20, or 40 μm diameter laser-drilled microhole, show significant current rectification in aqueous NaCl. Reconstituted α-cellulose films provide "cationic diodes" (due to predominant cation conductivity) whereas chitosan-doped cellulose shows "anionic diode" effects (due to predominant anion conductivity). The current rectification, or "ionic diode" behaviour, is investigated as a function of NaCl concentration, pH, microhole diameter, and molecular weight of the chitosan dopant. Future applications are envisaged exploiting the surface charge induced switching of diode currents for signal amplification in sensing.

  15. Cellulose Nanocrystals vs. Cellulose Nanofibrils: A Comparative study on Their Microstructures and Effects as Polymer Reinforcing Agents

    Science.gov (United States)

    Xuezhu Xu; Fei Liu; Long Jiang; J.Y. Zhu; Darrin Haagenson; Dennis P. Wiesenborn

    2013-01-01

    Both cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) are nanoscale cellulose fibers that have shown reinforcing effects in polymer nanocomposites. CNCs and CNFs are different in shape, size and composition. This study systematically compared their morphologies, crystalline structure, dispersion properties in polyethylene oxide (PEO) matrix, interactions...

  16. The productive cellulase binding capacity of cellulosic substrates.

    Science.gov (United States)

    Karuna, Nardrapee; Jeoh, Tina

    2017-03-01

    Cellulosic biomass is the most promising feedstock for renewable biofuel production; however, the mechanisms of the heterogeneous cellulose saccharification reaction are still unsolved. As cellulases need to bind isolated molecules of cellulose at the surface of insoluble cellulose fibrils or larger aggregated cellulose structures in order to hydrolyze glycosidic bonds, the "accessibility of cellulose to cellulases" is considered to be a reaction limiting property of cellulose. We have defined the accessibility of cellulose to cellulases as the productive binding capacity of cellulose, that is, the concentration of productive binding sites on cellulose that are accessible for binding and hydrolysis by cellulases. Productive cellulase binding to cellulose results in hydrolysis and can be quantified by measuring hydrolysis rates. In this study, we measured the productive Trichoderma reesei Cel7A (TrCel7A) binding capacity of five cellulosic substrates from different sources and processing histories. Swollen filter paper and bacterial cellulose had higher productive binding capacities of ∼6 µmol/g while filter paper, microcrystalline cellulose, and algal cellulose had lower productive binding capacities of ∼3 µmol/g. Swelling and regenerating filter paper using phosphoric acid increased the initial accessibility of the reducing ends to TrCel7A from 4 to 6 µmol/g. Moreover, this increase in initial productive binding capacity accounted in large part for the difference in the overall digestibility between filter paper and swollen filter paper. We further demonstrated that an understanding of how the productive binding capacity declines over the course of the hydrolysis reaction has the potential to predict overall saccharification time courses. Biotechnol. Bioeng. 2017;114: 533-542. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. On the polymorphic and morphological changes of cellulose nanocrystals (CNC-I) upon mercerization and conversion to CNC-II.

    Science.gov (United States)

    Jin, Ersuo; Guo, Jiaqi; Yang, Fang; Zhu, Yangyang; Song, Junlong; Jin, Yongcan; Rojas, Orlando J

    2016-06-05

    Polymorphic and morphological transformations of cellulosic materials are strongly associated to their properties and applications, especially in the case of emerging nanocelluloses. Related changes that take place upon treatment of cellulose nanocrystals (CNC) in alkaline conditions are studied here by XRD, TEM, AFM, and other techniques. The results indicate polymorphic transformation of CNC proceeds gradually in a certain range of alkali concentrations, i.e. from about 8% to 12.5% NaOH. In such transition alkali concentration, cellulose I and II allomorphs coexists. Such value and range of the transition concentration is strongly interdependent with the crystallite size of CNCs. In addition, it is distinctively lower than that for macroscopic fibers (12-15% NaOH). Transmission electron microscopy and particle sizing reveals that after mercerization CNCs tend to associate. Furthermore, TEMPO-oxidized mercerized CNC reveals the morphology of individual nanocrystal of the cellulose II type, which is composed of some interconnected granular structures. Overall, this work reveals how the polymorphism and morphology of individual CNC change in alkali conditions and sheds light onto the polymorphic transition from cellulose I to II. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Strong intrinsic motivation

    OpenAIRE

    Dessi, Roberta; Rustichini, Aldo

    2015-01-01

    A large literature in psychology, and more recently in economics, has argued that monetary rewards can reduce intrinsic motivation. We investigate whether the negative impact persists when intrinsic motivation is strong, and test this hypothesis experimentally focusing on the motivation to undertake interesting and challenging tasks, informative about individual ability. We find that this type of task can generate strong intrinsic motivation, that is impervious to the effect of monetary incen...

  19. Bitcoin Meets Strong Consistency

    OpenAIRE

    Decker, Christian; Seidel, Jochen; Wattenhofer, Roger

    2014-01-01

    The Bitcoin system only provides eventual consistency. For everyday life, the time to confirm a Bitcoin transaction is prohibitively slow. In this paper we propose a new system, built on the Bitcoin blockchain, which enables strong consistency. Our system, PeerCensus, acts as a certification authority, manages peer identities in a peer-to-peer network, and ultimately enhances Bitcoin and similar systems with strong consistency. Our extensive analysis shows that PeerCensus is in a secure state...

  20. Strong gravity and supersymmetry

    International Nuclear Information System (INIS)

    Chamseddine, Ali H.; Salam, A.; Strathdee, J.

    1977-11-01

    A supersymmetric theory is constructed for a strong f plus a weak g graviton, together with their accompanying massive gravitinos, by gaugin the gradel 0Sp(2,2,1)x 0Sp(2,2,1) structure. The mixing term between f and g fields, which makes the strong graviton massive, can be introduced through a spontaneous symmetry-breaking mechanism implemented in this note by constructing a non-linear realization of the symmetry group

  1. Adsorption of cationic amylopectin on microcrystalline cellulose.

    NARCIS (Netherlands)

    Steeg, van de H.G.M.; Keizer, de A.; Cohen Stuart, M.A.; Bijsterbosch, B.H.

    1993-01-01

    The effects of electrolyte concentration and pH on the adsorption of cationic amylopectin on microcrystalline cellulose were investigated. The adsorbed amount in the pseudo-plateau of the isotherm showed a maximum as a function of the electrolyte concentration. We compared the data with a recent

  2. Rapid saccharification for production of cellulosic biofuels.

    Science.gov (United States)

    Lee, Dae-Seok; Wi, Seung Gon; Lee, Soo Jung; Lee, Yoon-Gyo; Kim, Yeong-Suk; Bae, Hyeun-Jong

    2014-04-01

    The economical production of biofuels is hindered by the recalcitrance of lignocellulose to processing, causing high consumption of processing enzymes and impeding hydrolysis of pretreated lignocellulosic biomass. We determined the major rate-limiting factor in the hydrolysis of popping pre-treated rice straw (PPRS) by examining cellulase adsorption to lignin and cellulose, amorphogenesis of PPRS, and re-hydrolysis. Based on the results, equivalence between enzyme loading and the open structural area of cellulose was required to significantly increase productive adsorption of cellulase and to accelerate enzymatic saccharification of PPRS. Amorphogenesis of PPRS by phosphoric acid treatment to expand open structural area of the cellulose fibers resulted in twofold higher cellulase adsorption and increased the yield of the first re-hydrolysis step from 13% to 46%. The total yield from PPRS was increased to 84% after 3h. These results provide evidence that cellulose structure is one of major effects on the enzymatic hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Methacrylate hydrogels reinforced with bacterial cellulose

    Czech Academy of Sciences Publication Activity Database

    Hobzová, Radka; Dušková-Smrčková, Miroslava; Michálek, Jiří; Karpushkin, Evgeny; Gatenholm, P.

    2012-01-01

    Roč. 61, č. 7 (2012), s. 1193-1201 ISSN 0959-8103 R&D Projects: GA AV ČR KJB400500902 Institutional research plan: CEZ:AV0Z40500505 Keywords : bacterial cellulose * methacrylate hydrogel * composite Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.125, year: 2012

  4. Chemistry, Technology and Aplications of Oxidized Celluloses

    Czech Academy of Sciences Publication Activity Database

    Havelka, P.; Sopuch, T.; Hnatowicz, Vladimír; Suchý, P.; Masteikova, R.; Bajerová, M.; Gajdziok, J.; Milichovský, M.; Švorčík, V.

    2010-01-01

    Roč. 2010, C (2010), s. 205-245. ISBN 978-1-608-76-388-7 Institutional support: RVO:61389005 Keywords : oxidation * cellulose * in-vitro Subject RIV: BO - Biophysics https://www.novapublishers.com/catalog/product_info.php? products _id=14049

  5. Degradation of cellulose by basidiomycetous fungi

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Valášková, Vendula

    2008-01-01

    Roč. 32, č. 3 (2008), s. 501-521 ISSN 0168-6445 R&D Projects: GA MŠk LC06066; GA MZe QH72216 Institutional research plan: CEZ:AV0Z50200510 Keywords : cellobiohydrolase * cellulose dehydrogenase * basidiomycetes Subject RIV: EE - Microbiology, Virology Impact factor: 7.963, year: 2008

  6. Atomic force microscopy characterization of cellulose nanocrystals

    Science.gov (United States)

    Roya R. Lahiji; Xin Xu; Ronald Reifenberger; Arvind Raman; Alan Rudie; Robert J. Moon

    2010-01-01

    Cellulose nanocrystals (CNCs) are gaining interest as a “green” nanomaterial with superior mechanical and chemical properties for high-performance nanocomposite materials; however, there is a lack of accurate material property characterization of individual CNCs. Here, a detailed study of the topography, elastic and adhesive properties of individual wood-derived CNCs...

  7. Dynamics of water bound to crystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    O’Neill, Hugh; Pingali, Sai Venkatesh; Petridis, Loukas; He, Junhong; Mamontov, Eugene; Hong, Liang; Urban, Volker; Evans, Barbara; Langan, Paul; Smith, Jeremy C.; Davison, Brian H.

    2017-09-19

    Interactions of water with cellulose are of both fundamental and technological importance. Here, we characterize the properties of water associated with cellulose using deuterium labeling, neutron scattering and molecular dynamics simulation. Quasi-elastic neutron scattering provided quantitative details about the dynamical relaxation processes that occur and was supported by structural characterization using small-angle neutron scattering and X-ray diffraction. We can unambiguously detect two populations of water associated with cellulose. The first is “non-freezing bound” water that gradually becomes mobile with increasing temperature and can be related to surface water. The second population is consistent with confined water that abruptly becomes mobile at ~260 K, and can be attributed to water that accumulates in the narrow spaces between the microfibrils. Quantitative analysis of the QENS data showed that, at 250 K, the water diffusion coefficient was 0.85 ± 0.04 × 10-10 m2sec-1 and increased to 1.77 ± 0.09 × 10-10 m2sec-1 at 265 K. MD simulations are in excellent agreement with the experiments and support the interpretation that water associated with cellulose exists in two dynamical populations. Our results provide clarity to previous work investigating the states of bound water and provide a new approach for probing water interactions with lignocellulose materials.

  8. Saccharification of cellulosics by Microbispora bispora

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, Jr, C R; Eveleigh, D E

    1986-09-01

    The saccharification efficiency of cellulase from the thermophilic actinomycete Microbispora bispora was evaluated using commercially available feedstocks. The enzyme preparation was effective against refuse derived cellulose with 30% being converted to glucose in a 24 hour period. Pretreatment of the refuse with cadoxen resulted in an increase in saccharification efficiency to 70%.

  9. Nanomanufacturing metrology for cellulosic nanomaterials: an update

    Science.gov (United States)

    Postek, Michael T.

    2014-08-01

    The development of the metrology and standards for advanced manufacturing of cellulosic nanomaterials (or basically, wood-based nanotechnology) is imperative to the success of this rising economic sector. Wood-based nanotechnology is a revolutionary technology that will create new jobs and strengthen America's forest-based economy through industrial development and expansion. It allows this, previously perceived, low-tech industry to leap-frog directly into high-tech products and processes and thus improves its current economic slump. Recent global investments in nanotechnology programs have led to a deeper appreciation of the high performance nature of cellulose nanomaterials. Cellulose, manufactured to the smallest possible-size ( 2 nm x 100 nm), is a high-value material that enables products to be lighter and stronger; have less embodied energy; utilize no catalysts in the manufacturing, are biologically compatible and, come from a readily renewable resource. In addition to the potential for a dramatic impact on the national economy - estimated to be as much as $250 billion worldwide by 2020 - cellulose-based nanotechnology creates a pathway for expanded and new markets utilizing these renewable materials. The installed capacity associated with the US pulp and paper industry represents an opportunity, with investment, to rapidly move to large scale production of nano-based materials. However, effective imaging, characterization and fundamental measurement science for process control and characterization are lacking at the present time. This talk will discuss some of these needed measurements and potential solutions.

  10. [Insights into engineering of cellulosic ethanol].

    Science.gov (United States)

    Yue, Guojun; Wu, Guoqing; Lin, Xin

    2014-06-01

    For energy security, air pollution concerns, coupled with the desire to sustain the agricultural sector and revitalize the rural economy, many countries have applied ethanol as oxygenate or fuel to supplement or replace gasoline in transportation sector. Because of abundant feedstock resources and effective reduction of green-house-gas emissions, the cellulosic ethanol has attracted great attention. With a couple of pioneers beginning to produce this biofuel from biomass in commercial quantities around the world, it is necessary to solve engineering problems and complete the economic assessment in 2015-2016, gradually enter the commercialization stage. To avoid "competing for food with humans and competing for land with food", the 1st generation fuel ethanol will gradually transit to the 2nd generation cellulosic ethanol. Based on the overview of cellulosic ethanol industrialization from domestic and abroad in recent years, the main engineering application problems encountered in pretreatment, enzymes and enzymatic hydrolysis, pentose/hexose co-fermentation strains and processes, equipment were discussed from chemical engineering and biotechnology perspective. The development direction of cellulosic ethanol technology in China was addressed.

  11. Isolation and characterization of cellulose hydrolysing ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... A ruminant is any animal that digests its food in two steps, first by eating the raw ... within which the digestion of cellulose and other plant polysaccharides ... and adheres loosely to the plant cells wall, while. Pseudomonas and ...

  12. Characterization of cellulose nanowhiskers; Caracterizacao do nanowhiskers de celulose

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Nayra R.; Pinheiro, Ivanei F.; Morales, Ana R.; Ravagnani, Sergio P.; Mei, Lucia, E-mail: 25nareis@gmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2015-07-01

    Cellulose is the most abundant polymer earth. The cellulose nanowhiskers can be extracted from the cellulose. These have attracted attention for its use in nanostructured materials for various applications, such as nanocomposites, because they have peculiar characteristics, among them, high aspect ratio, biodegradability and excellent mechanical properties. This work aims to characterize cellulose nanowhiskers from microcrystalline cellulose. Therefore, these materials were characterized by X-ray diffraction (XRD) to assess the degree of crystallinity, infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) to the morphology of nanowhiskers and thermal stability was evaluated by Thermogravimetric Analysis (TGA). (author)

  13. Method of forming an electrically conductive cellulose composite

    Science.gov (United States)

    Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Woodward, Jonathan [Ashtead, GB

    2011-11-22

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  14. Preparation and characterization of nanocomposites of the carboxymethyl cellulose reinforced with cellulose nanocrystals; Preparacao e caracterizacao de nanocompositos de carboximetilcelulose reforcados com nanocristais de celulose

    Energy Technology Data Exchange (ETDEWEB)

    Flauzino Neto, Wilson P.; Silverio, Hudson A.; Vieira, Julia G.; Silva, Heden C.; Rosa, Joyce R.; Pasquini, Daniel, E-mail: wilsonpfneto@yahoo.com.br [Instituto de Quimica - Universidade Federal de Uberlandia - UFU, MG (Brazil); Assuncao, Rosana M.N. [Fac. de Ciencias Integradas do Pontal - FACIP, Universidade Federal de Uberlandia, Ituiutaba, MG (Brazil)

    2011-07-01

    Nanocrystals of cellulose (NCC) isolated from Eucalyptus urograndis Kraft pulp were used to prepare nanocomposites employing carboxymethyl cellulose (CMC) as matrix. The nanocrystals were isolated by hydrolysis with H{sub 2}SO{sub 4} 64% solution, for 20 minutes at 45 deg C. The nanocrystals were characterized by X-ray diffraction to evaluate the crystallinity of them. The amount of NCC used in the preparation of nanocomposites varied from 0 to 15%. The nanocomposites were characterized by thermal and mechanical analysis. A large reinforcing effect of NCC on the CMC matrix was observed. With the incorporation of the NCC, the tensile strength of nanocomposites was significantly improved by 107%, the elongation at break decreased by 48% and heat resistance to decomposition increased subtle. The improvement in thermo-mechanical properties are attributed to strong interactions between nanoparticles and CMC matrix. (author)

  15. Extraction of cellulose from pistachio shell and physical and mechanical characterisation of cellulose-based nanocomposites

    Science.gov (United States)

    Movva, Mounika; Kommineni, Ravindra

    2017-04-01

    Cellulose is an important nanoentity that have been used for the preparation of composites. The present work focuses on the extraction of cellulose from pistachio shell and preparing a partially degradable nanocomposite with extracted cellulose. Physical and microstructural characteristics of nanocellulose extracted from pistachio shell powder (PSP) through various stages of chemical treatment are identified from scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA). Later, characterized nanocellulose is reinforced in a polyester matrix to fabricate nanocellulose-based composites according to the ASTM standard. The resulting nanocellulose composite performance is evaluated in the mechanical perspective through tensile and flexural loading. SEM, FTIR, and XRD showed that the process for extraction is efficient in obtaining 95% crystalline cellulose. Cellulose also showed good thermal stability with a peak thermal degradation temperature of 361 °C. Such cellulose when reinforced in a matrix material showed a noteworthy rise in tensile and flexural strengths of 43 MPa and 127 MPa, at a definite weight percent of 5%.

  16. Pretreatment assisted synthesis and characterization of cellulose nanocrystals and cellulose nanofibers from absorbent cotton.

    Science.gov (United States)

    Abu-Danso, Emmanuel; Srivastava, Varsha; Sillanpää, Mika; Bhatnagar, Amit

    2017-09-01

    In this work, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were synthesized from absorbent cotton. Two pretreatments viz. dewaxing and bleaching with mild alkali were applied to the precursor (cotton). Acid hydrolysis was conducted with H 2 SO 4 and dissolution of cotton was achieved with a mixture of NaOH-thiourea-urea-H 2 O at -3°C. Synthesized cellulose samples were characterized using FTIR, XRD, SEM, BET, and zeta potential. It seems that synthesis conditions contributed to negative surface charge on cellulose samples and CNCs had the higher negative surface charge compared to CNFs. Furthermore, BET surface area, pore volume and pore diameter of CNCs were found to be higher as compared to CNFs. The dewaxed cellulose nanofibers (CNF D) had a slightly higher BET surface area (0.47m 2 /g) and bigger pore diameter (59.87Å) from attenuated contraction compared to waxed cellulose nanofibers (CNFW) (0.38m 2 /g and 44.89Å). The XRD of CNCs revealed a semi-crystalline structure and the dissolution agents influenced the crystallinity of CNFs. SEM images showed the porous nature of CNFs, the flaky nature and the nano-sized width of CNCs. Synthesized CNF D showed a better potential as an adsorbent with an average lead removal efficiency of 91.49% from aqueous solution. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Analysis of Twisting of Cellulose Nanofibrils in Atomistic Molecular Dynamics Simulations

    DEFF Research Database (Denmark)

    Paavilainen, S.; Rog, T.; Vattulainen, I.

    2011-01-01

    We use atomistic molecular dynamics simulations to study the crystal structure of cellulose nanofibrils, whose sizes are comparable with the crystalline parts in commercial nanocellulose. The simulations show twisting, whose rate of relaxation is strongly temperature dependent. Meanwhile......, no significant bending or stretching of nanocellulose is discovered. Considerations of atomic-scale interaction patterns bring about that the twisting arises from hydrogen bonding within and between the chains in a fibril....

  18. The Synthesis of a Novel Cellulose Physical Gel

    Directory of Open Access Journals (Sweden)

    Jiufang Duan

    2014-01-01

    Full Text Available Cellulose possessing β-cyclodextrin (β-CD was used as a host molecule and cellulose possessing ferrocene (Fc as a guest polymer. Infrared spectra, differential scanning calorimetry (DSC, ultraviolet spectroscopy (UV, and contact angle analysis were used to characterise the material structure and the inclusion behaviour. The results showed that the β-CD-cellulose and the Fc-cellulose can form inclusion complexes. Moreover, ferrocene oxidation, and reduction of state can be adjusted by sodium hypochlorite (NaClO as an oxidant and glutathione (GSH as a reductant. In this study, a physical gel based on β-CD-cellulose/Fc-cellulose was formed under mild conditions in which autonomous healing between cut surfaces occurred after 24 hours. The physical gel can be controlled in the sol-gel transition. The compressive strength of the Fc-cellulose/β-CD-cellulose gel increased with increased cellulose concentration. The host-guest interaction between the side chains of cellulose could strengthen the gel. The cellulose physical gel may eventually be used as a stimulus-responsive, healing material in biomedical applications.

  19. Assessing nano cellulose developments using science and technology indicators

    International Nuclear Information System (INIS)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues

    2013-01-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  20. Assessing nano cellulose developments using science and technology indicators

    Energy Technology Data Exchange (ETDEWEB)

    Milanez, Douglas Henrique; Amaral, Roniberto Morato do; Faria, Leandro Innocentini Lopes de; Gregolin, Jose Angelo Rodrigues, E-mail: douglasmilanez@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Nucleo de Informacao Tecnologica em Materiais. Dept. de Engenharia de Materiais

    2013-11-01

    This research aims to examine scientific and technological trends of developments in nano cellulose based on scientometric and patent indicators obtained from the Science Citation Index and Derwent Innovations Index in 2001-2010. The overall nano cellulose activity indicators were compared to nanotechnology and other selected nano materials. Scientific and technological future developments in nano cellulose were forecasted using extrapolation growth curves and the main countries were also mapped. The results showed that nano cellulose publications and patent documents have increased rapidly over the last five years with an average growth rate higher than that of nanotechnology and fullerene. The USA, Japan, France, Sweden and Finland all played a significant role in nano cellulose development and the extrapolation growth curves suggested that nano cellulose scientific and technological activities are still emerging. Finally, the evidence from this study recommends monitoring nano cellulose S and T advances in the coming years. (author)

  1. Azole-based antimycotic agents inhibit mold on unseasoned pine

    Science.gov (United States)

    Carol. A. Clausen; Vina W. Yang

    2005-01-01

    Inhibiting the growth of mold fungi on cellulose-based building materials may be achievable through the use of azole-based antimycotics. Azoles were variably effective against mold fungi that are frequently found on wood and wood products. Unseasoned southern yellow pine specimens that were dip-treated with varying concentrations of eight azoles were evaluated for...

  2. Morphology and physical-chemical properties of celluloses obtained by different methods

    Science.gov (United States)

    Anpilova, A. Yu.; Mastalygina, E. E.; Mikhaylov, I. A.; Popov, A. A.; Kartasheva, Z. S.

    2017-12-01

    The morphology and structural characteristics of celluloses obtained by different methods were studied. The objects of the investigation are cellulose from pulp source, commercial celluloses produced by sodium and acid hydrolysis, laboratory produced cellulose from bleached birch kraft pulp, and cellulose obtained by thermooxidative catalytic treatment of maple leaves by peroxide. According to a complex analysis of cellulose characteristics, several types of celluloses were offered as modifying additives for polymers.

  3. Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2013-05-01

    Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  4. IMPACTS OF BIOFILM FORMATION ON CELLULOSE FERMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Leschine, Susan

    2009-10-31

    This project addressed four major areas of investigation: i) characterization of formation of Cellulomonas uda biofilms on cellulose; ii) characterization of Clostridium phytofermentans biofilm development; colonization of cellulose and its regulation; iii) characterization of Thermobifida fusca biofilm development; colonization of cellulose and its regulation; and iii) description of the architecture of mature C. uda, C. phytofermentans, and T. fusca biofilms. This research is aimed at advancing understanding of biofilm formation and other complex processes involved in the degradation of the abundant cellulosic biomass, and the biology of the microbes involved. Information obtained from these studies is invaluable in the development of practical applications, such as the single-step bioconversion of cellulose-containing residues to fuels and other bioproducts. Our results have clearly shown that cellulose-decomposing microbes rapidly colonize cellulose and form complex structures typical of biofilms. Furthermore, our observations suggest that, as cells multiply on nutritive surfaces during biofilms formation, dramatic cell morphological changes occur. We speculated that morphological changes, which involve a transition from rod-shaped cells to more rounded forms, might be more apparent in a filamentous microbe. In order to test this hypothesis, we included in our research a study of biofilm formation by T. fusca, a thermophilic cellulolytic actinomycete commonly found in compost. The cellulase system of T. fusca has been extensively detailed through the work of David Wilson and colleagues at Cornell, and also, genome sequence of a T. fusca strain has been determine by the DOE Joint Genome Institute. Thus, T. fusca is an excellent subject for studies of biofilm development and its potential impacts on cellulose degradation. We also completed a study of the chitinase system of C. uda. This work provided essential background information for understanding how C. uda

  5. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  6. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  7. Influence of polystyrene addition to cellulose on chemical structure and properties of bio-oil obtained during pyrolysis

    International Nuclear Information System (INIS)

    Rutkowski, Piotr; Kubacki, Andrzej

    2006-01-01

    The cellulose (C), polystyrene (PS) and cellulose/polystyrene (C-PS) mixtures (3:1, 1:1, 1:3 w/w) were subjected to a pyrolysis process to produce bio-oil. The pyrolytic oil yield was in the range of 45.5-94.8 wt% depending on the composition of the sample. Pyrolysis of polystyrene gives the highest oil yield, whereas for cellulose, the yield of liquid products was the lowest. The basic physicochemical properties of oils are strongly influenced by the original material and do not change additively. The polystyrene addition to cellulose clearly improves the quality of the bio-oil, resulting in decreases in acid number, pour point and density. The change of color is not so distinct. The FT-IR analysis of the oils showed that the oxygen functionalities and hydrocarbons contents highly depend on the composition of the cellulose/polystyrene mixture. The fractionation of bio-oils by column chromatography using hexane and benzene was followed by GC-MS analyses. Different classes of organic compounds were identified, i.e., carboxylic acids, phenols, aldehydes, ketones, esters, ethers and unsaturated linear and cyclic hydrocarbons. The proportion of hydrocarbons increases with a decrease of the cellulose/polystyrene ratio. The obtained results indicate that during pyrolysis, not only does decomposition of cellulose and polystyrene occur, but also, reactions between products from C and PS take place. That was proved by the presence of compounds identified only in the bio-oils obtained from C-PS compositions

  8. Identification and Characterization of Non-Cellulose-Producing Mutants of Gluconacetobacter hansenii Generated by Tn5 Transposon Mutagenesis

    Science.gov (United States)

    Deng, Ying; Nagachar, Nivedita; Xiao, Chaowen; Tien, Ming

    2013-01-01

    The acs operon of Gluconacetobacter is thought to encode AcsA, AcsB, AcsC, and AcsD proteins that constitute the cellulose synthase complex, required for the synthesis and secretion of crystalline cellulose microfibrils. A few other genes have been shown to be involved in this process, but their precise role is unclear. We report here the use of Tn5 transposon insertion mutagenesis to identify and characterize six non-cellulose-producing (Cel−) mutants of Gluconacetobacter hansenii ATCC 23769. The genes disrupted were acsA, acsC, ccpAx (encoding cellulose-complementing protein [the subscript “Ax” indicates genes from organisms formerly classified as Acetobacter xylinum]), dgc1 (encoding guanylate dicyclase), and crp-fnr (encoding a cyclic AMP receptor protein/fumarate nitrate reductase transcriptional regulator). Protein blot analysis revealed that (i) AcsB and AcsC were absent in the acsA mutant, (ii) the levels of AcsB and AcsC were significantly reduced in the ccpAx mutant, and (iii) the level of AcsD was not affected in any of the Cel− mutants. Promoter analysis showed that the acs operon does not include acsD, unlike the organization of the acs operon of several strains of closely related Gluconacetobacter xylinus. Complementation experiments confirmed that the gene disrupted in each Cel− mutant was responsible for the phenotype. Quantitative real-time PCR and protein blotting results suggest that the transcription of bglAx (encoding β-glucosidase and located immediately downstream from acsD) was strongly dependent on Crp/Fnr. A bglAx knockout mutant, generated via homologous recombination, produced only ∼16% of the wild-type cellulose level. Since the crp-fnr mutant did not produce any cellulose, Crp/Fnr may regulate the expression of other gene(s) involved in cellulose biosynthesis. PMID:24013627

  9. Defining Determinants and Dynamics and Cellulose Microfibril Biosynthesis, Assembly and Degredation OSP Number: 63079/A001

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2013-12-01

    been based on the idea that the most effective way to address this long standing and highly complex question is to adopt a broad ‘systems approach’. Accordingly, we assembled a multi-disciplinary collaborative team with collective expertise in plant biology and molecular genetics, polymer structure and chemistry, enzyme biochemistry and biochemical engineering. We used a spectrum of cutting edge technologies, including plant functional genomics, chemical genetics, live cell imaging, advanced microscopy, high energy X-ray spectroscopy and nanotechnology, to study the molecular determinants of cellulose microfibril structure. Importantly, this research effort was closely coupled with an analytical pipeline to characterize the effects of altering microfibril architecture on bioconversion potential, with the goal of generating predictive models to help guide the identification, development and implementation of new feedstocks. This project therefore spanned core basic science and applied research, in line with the goals of the program. Over the course of the project, accomplishments included: - Establishing platforms through reverse and forward genetics to identify and manipulate candidate genes that influence cellulose microfibril synthesis and structure in a model C3 grass, Brachypodium distachyon and a model C4 grass Setaria viridis; Identifying and characterizing the effects of a number of cellulose biosynthesis inhibitors (CBIs), and particularly those that target monocots with the aim of generating resistance loci; Developing protocols for the use of high energy X-ray diffraction (XRD) to study the structure and organization of cellulose microfibrils in plant walls, notably those in Arabidopsis and Brachypodium; Using the chemical and genetic based inhibition strategies to develop new mechanistic models of cellulose microfibril crystallization, and of how altering microfibril architecture influences digestibility.

  10. Isolation of cellulose fibers from kenaf using electron beam

    International Nuclear Information System (INIS)

    Shin, Hye Kyoung; Pyo Jeun, Joon; Bin Kim, Hyun; Hyun Kang, Phil

    2012-01-01

    Cellulose fibers were isolated from a kenaf bast fiber using a electron beam irradiation (EBI) treatment. The methods of isolation were based on a hot water treatment after EBI and two-step bleaching processes. FT-IR spectroscopy demonstrated that the content of lignin and hemicellulose in the bleached cellulose fibers treated with various EBI doses decreased with increasing doses of EBI. Specifically, the lignin in the bleached cellulose fibers treated at 300 kGy, was almost completely removed. Moreover, XRD analyses showed that the bleached cellulose fibers treated at 300 kGy presented the highest crystallinity of all the samples treated with EBI. Finally, the morphology of the bleached fiber was characterized by SEM imagery, and the studies showed that the separated degree of bleached cellulose fibers treated with various EBI doses increased with an increase of EBI dose, and the bleached cellulose fibers obtained by EBI treatment at 300 kGy was separated more uniformly than the bleached cellulose fiber obtained by alkali cooking with non-irradiated kenaf fiber. - Highlights: ► This study was to provide a progressive and convenient cellulose isolation process. ► Using an electron beam irradiation, we can obtain cellulose fibers using only water without chemicals during cooking process. ► We think that this cellulose isolation method will have an effect on enormous environmental and economic benefits.

  11. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  12. Synthesis and characterization of composite based on cellulose acetate and hydroxyapatite application to the absorption of harmful substances.

    Science.gov (United States)

    Azzaoui, Khalil; Lamhamdi, Abdelatif; Mejdoubi, El Miloud; Berrabah, Mohammed; Hammouti, Belkheir; Elidrissi, Abderrahman; Fouda, Moustafa M G; Al-Deyab, Salem S

    2014-10-13

    The aim of this work is to develop composite materials with hydroxyapatite (HAp) mineral and organic matrix such as cellulosic polymers. We use cellulose acetate with different percentages, and then inorganic-organic films were fabricated by evaporation of solvent. The composite films were characterized using emission scanning electron microscopy (FEG-SEM), thermo-gravimetric analysis (TGA) and Fourier transform infra-red (FT-IR) spectra. Test results show that these films are uniform and have good ductility. A strong interaction existed between HAp and cellulosic polymers, and the method allows the production of very fine particles size of about 92 nm. We have developed a new chromatographic method for the quantification of bisphenol A (BPA) in samples of baby food. The result of this study demonstrates how to use this type of composite materials to remove pollutants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Retention of Cationic Starch onto Cellulose Fibres

    Science.gov (United States)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  14. Cellulose and the Control of Growth Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Tobias I. Baskin

    2004-04-01

    The authors research aims to understand morphogenesis, focusing on growth anisotropy, a process that is crucial to make organs with specific and heritable shapes. For the award, the specific aims were to test hypotheses concerning how growth anisotropy is controlled by cell wall structure, particularly by the synthesis and alignment of cellulose microfibrils, the predominant mechanical element in the cell wall. This research has involved characterizing the basic physiology of anisotropic expansion, including measuring it at high resolution; and second, characterizing the relationship between growth anisotropy, and cellulose microfibrils. Important in this relationship and also to the control of anisotropic expansion are structures just inside the plasma membrane called cortical microtubules, and the research has also investigated their contribution to controlling anisotropy and microfibril alignment. In addition to primary experimental papers, I have also developed improved methods relating to these objectives as well as written relevant reviews. Major accomplishments in each area will now be described.

  15. Reinforced plastics and aerogels by nanocrystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Alfred C. W.; Lam, Edmond; Chong, Jonathan; Hrapovic, Sabahudin; Luong, John H. T., E-mail: john.luong@cnrc-nrc.gc.ca [National Research Council Canada (Canada)

    2013-05-15

    Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect.

  16. Using carboxylated nanocrystalline cellulose as an additive in cellulosic paper and poly (vinyl alcohol) fiber paper.

    Science.gov (United States)

    Cha, Ruitao; Wang, Chengyu; Cheng, Shaoling; He, Zhibin; Jiang, Xingyu

    2014-09-22

    Specialty paper (e.g. cigarette paper and battery diaphragm paper) requires extremely high strength properties. The addition of strength agents plays an important role in increasing strength properties of paper. Nanocrystalline cellulose (NCC), or cellulose whiskers, has the potential to enhance the strength properties of paper via improving inter-fibers bonding. This paper was to determine the potential of using carboxylated nanocrystalline cellulose (CNCC) to improve the strength properties of paper made of cellulosic fiber or poly (vinyl alcohol) (PVA) fiber. The results indicated that the addition of CNCC can effectively improve the strength properties. At a CNCC dosage of 0.7%, the tear index and tensile index of the cellulosic paper reached the maximum of 12.8 mN m2/g and 100.7 Nm/g, respectively. More importantly, when increasing the CNCC dosage from 0.1 to 1.0%, the tear index and tensile index of PVA fiber paper were increased by 67.29%, 22.55%, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  18. Super-resolution imaging with Pontamine Fast Scarlet 4BS enables direct visualization of cellulose orientation and cell connection architecture in onion epidermis cells

    DEFF Research Database (Denmark)

    Liesche, Johannes; Ziomkiewicz, Iwona; Schulz, Alexander

    2013-01-01

    of cellulose fibril orientation and growth. The fluorescent dye Pontamine Fast Scarlet 4BS (PFS) was shown to stain cellulose with high specificity and could be used to visualize cellulose bundles in cell walls of Arabidopsis root epidermal cells with confocal microscopy. The resolution limit of confocal...... present the first super-resolution images of cellulose bundles in the plant cell wall produced by direct stochastic optical reconstruction microscopy (dSTORM) in combination with total internal reflection fluorescence (TIRF) microscopy. Since TIRF limits observation to the cell surface, we tested...... as alternatives 3D-structured illumination microscopy (3D-SIM) and confocal microscopy, combined with image deconvolution. Both methods offer lower resolution than STORM, but enable 3D imaging. While 3D-SIM produced strong artifacts, deconvolution gave good results. The resolution was improved over conventional...

  19. Hydrophilic/hydrophobic character of grafted cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, E., E-mail: takacs@iki.kfki.h [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary); Wojnarovits, L. [Institute of Isotopes, Hungarian Academy of Sciences, Budapest (Hungary); Borsa, J. [Budapest University of Technology and Economics (Hungary); Racz, I. [Bay Zoltan Institute for Materials Science and Technology, Budapest (Hungary)

    2010-04-15

    Vinyl monomers with long paraffin chains were grafted onto two kinds of cellulose (cotton and cotton linter) by direct irradiation grafting technique. The effect of dose, monomer structure and concentration, as well as homopolymer suppressor (styrene) concentration on the grafting yield was studied and the optimal grafting conditions were established. Grafting decreased the swelling of the samples in water and increased their polymer compatibility in polypropylene matrix.

  20. Enzyme hydrolysis of waste cellulose. [Aspergillus awamori

    Energy Technology Data Exchange (ETDEWEB)

    Mustranta, A; Nybergh, P; Hatakka, A

    1976-01-01

    Hydrolysis of brewers' spent grain and of wastes from the furfural process was investigated with culture filtrates from Trichoderma viride and Aspergillus awamori. The furfural process is evidently a good pretreatment for cellulose, and no further pretreatment is needed. Syrups containing 5% reducing sugars and 3-4% glucose were obtained from furfural process wastes and hydrolyzates containing 1.5% reducing sugars and 0.7% glucose were obtained from brewers' spent grains.

  1. Cellulose triacetate, thin film dielectric capacitor

    Science.gov (United States)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1995-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  2. Production of ethanol from cellulose (sawdust)

    OpenAIRE

    Otulugbu, Kingsley

    2012-01-01

    The production of ethanol from food such as corn, cassava etc. is the most predominate way of producing ethanol. This has led to a shortage in food, inbalance in food chain, increased food price and indirect land use. This thesis thus explores using another feed for the production of ethanol- hence ethanol from cellulose. Sawdust was used to carry out the experiment from the production of ethanol and two methods were considered: SHF (Separate Hydrolysis and Fermentation) and SSF (Simultaneous...

  3. Development of efficient, integrated cellulosic biorefineries : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Teh, Kwee-Yan; Hecht, Ethan S.; Shaddix, Christopher R.; Buffleben, George M.; Dibble, Dean C.; Lutz, Andrew E.

    2010-09-01

    Cellulosic ethanol, generated from lignocellulosic biomass sources such as grasses and trees, is a promising alternative to conventional starch- and sugar-based ethanol production in terms of potential production quantities, CO{sub 2} impact, and economic competitiveness. In addition, cellulosic ethanol can be generated (at least in principle) without competing with food production. However, approximately 1/3 of the lignocellulosic biomass material (including all of the lignin) cannot be converted to ethanol through biochemical means and must be extracted at some point in the biochemical process. In this project we gathered basic information on the prospects for utilizing this lignin residue material in thermochemical conversion processes to improve the overall energy efficiency or liquid fuel production capacity of cellulosic biorefineries. Two existing pretreatment approaches, soaking in aqueous ammonia (SAA) and the Arkenol (strong sulfuric acid) process, were implemented at Sandia and used to generated suitable quantities of residue material from corn stover and eucalyptus feedstocks for subsequent thermochemical research. A third, novel technique, using ionic liquids (IL) was investigated by Sandia researchers at the Joint Bioenergy Institute (JBEI), but was not successful in isolating sufficient lignin residue. Additional residue material for thermochemical research was supplied from the dilute-acid simultaneous saccharification/fermentation (SSF) pilot-scale process at the National Renewable Energy Laboratory (NREL). The high-temperature volatiles yields of the different residues were measured, as were the char combustion reactivities. The residue chars showed slightly lower reactivity than raw biomass char, except for the SSF residue, which had substantially lower reactivity. Exergy analysis was applied to the NREL standard process design model for thermochemical ethanol production and from a prototypical dedicated biochemical process, with process data

  4. Cellulose nanoparticles: photoacoustic contrast agents that biodegrade to simple sugars

    Science.gov (United States)

    Jokerst, Jesse V.; Bohndiek, Sarah E.; Gambhir, Sanjiv S.

    2014-03-01

    In photoacoustic imaging, nanoparticle contrast agents offer strong signal intensity and long-term stability, but are limited by poor biodistribution and clearance profiles. Conversely, small molecules offer renal clearance, but relatively low photoacoustic signal. Here we describe a cellulose-based nanoparticle with photoacoustic signal superior to gold nanorods, but that undergoes enzymatic cleavage into constituent glucose molecules for renal clearance. Cellulose nanoparticles (CNPs) were synthesized through acidic cleavage of cellulose linters and purified with centrifugation. TEM indicated that the nanoparticles were 132 +/- 46 nm; the polydispersity index was 0.138. Ex vivo characterization showed a photoacoustic limit of detection of 0.02 mg/mL CNPs, and the photoacoustic signal of CNPs was 1.5- to 3.0-fold higher than gold nanorods (also at 700 nm resonance) on a particle-to-particle basis. Cell toxicity assays suggested that overnight doses below 0.31 mg/mL CNPs produced no significant (p>0.05) impact on cell metabolism. Intravenous doses up to 0.24 mg were tolerated well in nude mice. Subcutaneous and orthotopic tumor xenografts of the OV2008 ovarian cancer cell line were then created in nude mice. Data was collected with a Nexus128 scanner from Endra LifeSciences. Spectral data used a LAZR system from Visualsonics both at 700 nm excitation. We injected CNPs (0.024 mg, 0.048 mg, and 0.80 mg) via tail vein and showed that the tumor photoacoustic signal reached maximum increase between 10 and 20 minutes. All injected concentrations were statistically (p0.96 suggesting quantitative signal. CNP biodegradation was demonstrated ex vivo with a glucose assay. CNPs in the presence of cellulase were reduced to free glucose in under than four hours. The glucose concentration before addition of cellulase was not detectable, but increased to 92.1 μg/mL in four hours. CNPs in the absence of cellulase did not produce glucose. Small fragments of nanoparticle in the

  5. Ultrasound-assisted dyeing of cellulose acetate.

    Science.gov (United States)

    Udrescu, C; Ferrero, F; Periolatto, M

    2014-07-01

    The possibility of reducing the use of auxiliaries in conventional cellulose acetate dyeing with Disperse Red 50 using ultrasound technique was studied as an alternative to the standard procedure. Dyeing of cellulose acetate yarn was carried out by using either mechanical agitation alone, with and without auxiliaries, or coupling mechanical and ultrasound agitation in the bath where the temperature range was maintained between 60 and 80 °C. The best results of dyeing kinetics were obtained with ultrasound coupled with mechanical agitation without auxiliaries (90% of bath exhaustion value at 80 °C). Hence the corresponding half dyeing times, absorption rate constants according to Cegarra-Puente modified equation and ultrasound efficiency were calculated confirming the synergic effect of sonication on the dyeing kinetics. Moreover the apparent activation energies were also evaluated and the positive effect of ultrasound added to mechanical agitation was evidenced by the lower value (48 kJ/mol) in comparison with 112 and 169 kJ/mol for mechanical stirring alone with auxiliaries and without, respectively. Finally, the fastness tests gave good values for samples dyed with ultrasound technique even without auxiliaries. Moreover color measurements on dyed yarns showed that the color yield obtained by ultrasound-assisted dyeing at 80 °C of cellulose acetate without using additional chemicals into the dye bath reached the same value yielded by mechanical agitation, but with remarkably shorter time. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Tritium concentrations in tree ring cellulose

    International Nuclear Information System (INIS)

    Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

    1989-01-01

    Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

  7. Enzymatic Systems for Cellulose Acetate Degradation

    Directory of Open Access Journals (Sweden)

    Oskar Haske-Cornelius

    2017-09-01

    Full Text Available Cellulose acetate (CA-based materials, like cigarette filters, contribute to landscape pollution challenging municipal authorities and manufacturers. This study investigates the potential of enzymes to degrade CA and to be potentially incorporated into the respective materials, enhancing biodegradation. Deacetylation studies based on Liquid Chromatography-Mass Spectrometry-Time of Flight (LC-MS-TOF, High Performance Liquid Chromatography (HPLC, and spectrophotometric analysis showed that the tested esterases were able to deacetylate the plasticizer triacetin (glycerol triacetate and glucose pentaacetate (cellulose acetate model compound. The most effective esterases for deacetylation belong to the enzyme family 2 (AXE55, AXE 53, GAE, they deacetylated CA with a degree of acetylation of up to 1.8. A combination of esterases and cellulases showed synergistic effects, the absolute glucose recovery for CA 1.8 was increased from 15% to 28% when an enzymatic deacetylation was performed. Lytic polysaccharide monooxygenase (LPMO, and cellobiohydrolase were able to cleave cellulose acetates with a degree of acetylation of up to 1.4, whereas chitinase showed no activity. In general, the degree of substitution, chain length, and acetyl group distribution were found to affect CA degradation. This study shows that, for a successful enzyme-based deacetylation system, a cocktail of enzymes, which will randomly cleave and generate shorter CA fragments, is the most suitable.

  8. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K [Idaho National Laboratory; Jacobson, Jacob Jordan [Idaho National Laboratory; Cafferty, Kara Grace [Idaho National Laboratory; Lamers, Patrick [Idaho National Laboratory; Roni, MD S [Idaho National Laboratory

    2015-03-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  9. Quantifying Supply Risk at a Cellulosic Biorefinery

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Jason K.; Jacobson, Jacob J.; Cafferty, Kara G.; Lamers, Patrick; Roni, Mohammad S.

    2015-07-01

    In order to increase the sustainability and security of the nation’s energy supply, the U.S. Department of Energy through its Bioenergy Technology Office has set a vision for one billion tons of biomass to be processed for renewable energy and bioproducts annually by the year 2030. The Renewable Fuels Standard limits the amount of corn grain that can be used in ethanol conversion sold in the U.S, which is already at its maximum. Therefore making the DOE’s vision a reality requires significant growth in the advanced biofuels industry where currently three cellulosic biorefineries convert cellulosic biomass to ethanol. Risk mitigation is central to growing the industry beyond its infancy to a level necessary to achieve the DOE vision. This paper focuses on reducing the supply risk that faces a firm that owns a cellulosic biorefinery. It uses risk theory and simulation modeling to build a risk assessment model based on causal relationships of underlying, uncertain, supply driving variables. Using the model the paper quantifies supply risk reduction achieved by converting the supply chain from a conventional supply system (bales and trucks) to an advanced supply system (depots, pellets, and trains). Results imply that the advanced supply system reduces supply system risk, defined as the probability of a unit cost overrun, from 83% in the conventional system to 4% in the advanced system. Reducing cost risk in this nascent industry improves the odds of realizing desired growth.

  10. Extraction and characterization of cellulose nano whiskers from balsa wood

    International Nuclear Information System (INIS)

    Morelli, Carolina L.; Bretas, Rosario E.S.; Marconcini, Jose M.; Pereira, Fabiano V.; Branciforti, Marcia C.

    2011-01-01

    In this study cellulose nano whiskers were obtained from balsa wood. For this purpose, fibers of balsa wood were subjected to hydrolysis reactions for lignin and hemi cellulose digestion and acquisition of nano-scale cellulose. Cellulose nano crystals obtained had medium length and thickness of 176 nm and 7 nm respectively. Infrared spectroscopy and x-ray diffraction showed that the process used for extracting nano whiskers could digest nearly all the lignin and hemi cellulose from the balsa fiber and still preserve the aspect ratio and crystallinity, satisfactory enough for future application in polymer nano composites. Thermogravimetry showed that the onset temperature of thermal degradation of cellulose nano crystals (226 degree C) was higher than the temperature of the balsa fiber (215 degree C), allowing its use in molding processes with many polymers from the molten state.(author)

  11. One-step Fabrication of Cellulose/Graphene Conductive Paper

    Institute of Scientific and Technical Information of China (English)

    KaiWen Mou; LuMing Yang; HuangWei Xiong; RuiTao Cha

    2017-01-01

    In this study,a straightforward,one-step wet-end formation process was employed to prepare cellulose/graphene conductive paper for antistatic packing materials.Cationic polyacrylamide was introduced into the cellulose/graphene slurry to improve the graphene loading on the surfaces of the cellulose fibers.The effect of the super calender process on the properties of the cellulose/graphene conductive paper was investigated.When 55 wt% graphene was added,the volume resistivity of the cellulose/graphene conductive paper was 94.70 Ω·cm,decreasing to 35.46 Ω·cm after the super calender process.The cellulose/graphene conductive paper possessed excellent anti-static ability and could be used as an anti-static material.

  12. Enhanced hydrolysis of cellulose hydrogels by morphological modification.

    Science.gov (United States)

    Alfassi, Gilad; Rein, Dmitry M; Cohen, Yachin

    2017-11-01

    Cellulose is one of the most abundant bio-renewable materials on earth, yet the potential of cellulosic bio-fuels is not fully exploited, primarily due to the high costs of conversion. Hydrogel particles of regenerated cellulose constitute a useful substrate for enzymatic hydrolysis, due to their porous and amorphous structure. This article describes the influence of several structural aspects of the cellulose hydrogel on its hydrolysis. The hydrogel density was shown to be directly proportional to the cellulose concentration in the initial solution, thus affecting its hydrolysis rate. Using high-resolution scanning electron microscopy, we show that the hydrogel particles in aqueous suspension exhibit a dense external surface layer and a more porous internal network. Elimination of the external surface layer accelerated the hydrolysis rate by up to sixfold and rendered the process nearly independent of cellulose concentration. These findings may be of practical relevance to saccharification processing costs, by reducing required solvent quantities and enzyme load.

  13. Structure and transformation of tactoids in cellulose nanocrystal suspensions

    Science.gov (United States)

    Wang, Pei-Xi; Hamad, Wadood Y.; MacLachlan, Mark J.

    2016-05-01

    Cellulose nanocrystals obtained from natural sources are of great interest for many applications. In water, cellulose nanocrystals form a liquid crystalline phase whose hierarchical structure is retained in solid films after drying. Although tactoids, one of the most primitive components of liquid crystals, are thought to have a significant role in the evolution of this phase, they have evaded structural study of their internal organization. Here we report the capture of cellulose nanocrystal tactoids in a polymer matrix. This method allows us to visualize, for the first time, the arrangement of cellulose nanocrystals within individual tactoids by electron microscopy. Furthermore, we can follow the structural evolution of the liquid crystalline phase from tactoids to iridescent-layered films. Our insights into the early nucleation events of cellulose nanocrystals give important information about the growth of cholesteric liquid crystalline phases, especially for cellulose nanocrystals, and are crucial for preparing photonics-quality films.

  14. Enzymatic hydrolysis of biomimetic bacterial cellulose-hemicellulose composites.

    Science.gov (United States)

    Penttilä, Paavo A; Imai, Tomoya; Hemming, Jarl; Willför, Stefan; Sugiyama, Junji

    2018-06-15

    The production of biofuels and other chemicals from lignocellulosic biomass is limited by the inefficiency of enzymatic hydrolysis. Here a biomimetic composite material consisting of bacterial cellulose and wood-based hemicelluloses was used to study the effects of hemicelluloses on the enzymatic hydrolysis with a commercial cellulase mixture. Bacterial cellulose synthesized in the presence of hemicelluloses, especially xylan, was found to be more susceptible to enzymatic hydrolysis than hemicellulose-free bacterial cellulose. The reason for the easier hydrolysis could be related to the nanoscale structure of the substrate, particularly the packing of cellulose microfibrils into ribbons or bundles. In addition, small-angle X-ray scattering was used to show that the average nanoscale morphology of bacterial cellulose remained unchanged during the enzymatic hydrolysis. The reported easier enzymatic hydrolysis of bacterial cellulose produced in the presence of wood-based xylan offers new insights to overcome biomass recalcitrance through genetic engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Cellulose-Based Bio- and Nanocomposites: A Review

    Directory of Open Access Journals (Sweden)

    Susheel Kalia

    2011-01-01

    Full Text Available Cellulose macro- and nanofibers have gained increasing attention due to the high strength and stiffness, biodegradability and renewability, and their production and application in development of composites. Application of cellulose nanofibers for the development of composites is a relatively new research area. Cellulose macro- and nanofibers can be used as reinforcement in composite materials because of enhanced mechanical, thermal, and biodegradation properties of composites. Cellulose fibers are hydrophilic in nature, so it becomes necessary to increase their surface roughness for the development of composites with enhanced properties. In the present paper, we have reviewed the surface modification of cellulose fibers by various methods. Processing methods, properties, and various applications of nanocellulose and cellulosic composites are also discussed in this paper.

  16. Metallization of bacterial cellulose for electrical and electronic device manufacture

    Science.gov (United States)

    Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN; Jansen, Valerie Malyvanh [Memphis, TN; Woodward, Jonathan [Knoxville, TN

    2010-09-28

    A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

  17. A xylanase-aided enzymatic pretreatment facilitates cellulose nanofibrillation.

    Science.gov (United States)

    Long, Lingfeng; Tian, Dong; Hu, Jinguang; Wang, Fei; Saddler, Jack

    2017-11-01

    Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment. It showed that the synergistic cooperation between endoglucanase and certain xylanase (Biobrite) could efficiently "open up" the hardwood Kraft pulp with limited carbohydrates degradation (cellulose nanofibrillation during mild sonication process (90Wh) with more uniform disintegrated nanofibril products (50-150nm, as assessed by scanning electron microscopy and UV-vis spectroscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Crystallographic snapshot of cellulose synthesis and membrane translocation.

    Science.gov (United States)

    Morgan, Jacob L W; Strumillo, Joanna; Zimmer, Jochen

    2013-01-10

    Cellulose, the most abundant biological macromolecule, is an extracellular, linear polymer of glucose molecules. It represents an essential component of plant cell walls but is also found in algae and bacteria. In bacteria, cellulose production frequently correlates with the formation of biofilms, a sessile, multicellular growth form. Cellulose synthesis and transport across the inner bacterial membrane is mediated by a complex of the membrane-integrated catalytic BcsA subunit and the membrane-anchored, periplasmic BcsB protein. Here we present the crystal structure of a complex of BcsA and BcsB from Rhodobacter sphaeroides containing a translocating polysaccharide. The structure of the BcsA-BcsB translocation intermediate reveals the architecture of the cellulose synthase, demonstrates how BcsA forms a cellulose-conducting channel, and suggests a model for the coupling of cellulose synthesis and translocation in which the nascent polysaccharide is extended by one glucose molecule at a time.

  19. Biodegradation evaluation of bacterial cellulose, vegetable cellulose and poly (3-hydroxybutyrate in soil

    Directory of Open Access Journals (Sweden)

    Suellen Brasil Schröpfer

    2015-04-01

    Full Text Available In recent years, the inappropriate disposal of polymeric materials has increased due to industrial development and increase of population consumption. This problem may be minimized by using biodegradable polymers, such as bacterial cellulose and poly(hydroxybutyrate, from renewable resources. This work was aimed at monitoring and evaluating degradation of bacterial cellulose, vegetable cellulose and poly(3-hydroxybutyrate using Thermogravimetric Analysis and Scanning Electron Microscopy. Controlled mass polymer samples were buried in pots containing soil. Samples were removed in 30 day intervals up to 180 days. The results show that the mass of the polymer increased in the first month when in contact with the soil but then it was degraded as evidenced by mass loss and changes on the sample surface.

  20. Strongly intensive quantities

    International Nuclear Information System (INIS)

    Gorenstein, M. I.; Gazdzicki, M.

    2011-01-01

    Analysis of fluctuations of hadron production properties in collisions of relativistic particles profits from use of measurable intensive quantities which are independent of system size variations. The first family of such quantities was proposed in 1992; another is introduced in this paper. Furthermore we present a proof of independence of volume fluctuations for quantities from both families within the framework of the grand canonical ensemble. These quantities are referred to as strongly intensive ones. Influence of conservation laws and resonance decays is also discussed.

  1. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  2. Improvement of tolerance of Saccharomyces cerevisiae to hot-compressed water-treated cellulose by expression of ADH1

    Energy Technology Data Exchange (ETDEWEB)

    Jayakody, Lahiru N.; Horie, Kenta; Kitagaki, Hiroshi [Saga Univ. (Japan). Dept. of Environmental Sciences; Hayashi, Nobuyuki [Saga Univ. (Japan). Dept. of Applied Biochemistry and Food Science

    2012-04-15

    Hot-compressed water treatment of cellulose and hemicellulose for subsequent bioethanol production is a novel, economically feasible, and nonhazardous method for recovering sugars. However, the hot-compressed water-treated cellulose and hemicellulose inhibit subsequent ethanol fermentation by the yeast Saccharomyces cerevisiae. To overcome this problem, we engineered a yeast strain with improved tolerance to hot-compressed water-treated cellulose. We first determined that glycolaldehyde has a greater inhibitory effect than 5-HMF and furfural and a combinational effect with them. On the basis of the hypothesis that the reduction of glycolaldehyde to ethylene glycol should detoxify glycolaldehyde, we developed a strain overexpressing the alcohol dehydrogenase gene ADH1. The ADH1-overexpressing strain exhibits an improved fermentation profile in a glycolaldehyde-containing medium. The conversion ratio of glycolaldehyde to ethylene glycol is 30 {+-} 1.9% when the control strain is used; this ratio increases to 77 {+-} 3.6% in the case of the ADH1-overexpressing strain. A glycolaldehyde treatment and the overexpression of ADH1 cause changes in the fermentation products so as to balance the metabolic carbon flux and the redox status. Finally, the ADH1-overexpressing strain shows a statistically significantly improved fermentation profile in a hot-compressed water-treated cellulose-containing medium. The conversion ratio of glycolaldehyde to ethylene glycol is 33 {+-} 0.85% when the control strain is used but increases to 72 {+-} 1.7% in the case of the ADH1-overexpressing strain. These results show that the reduction of glycolaldehyde to ethylene glycol is a promising strategy to decrease the toxicity of hot-compressed water-treated cellulose. This is the first report on the improvement of yeast tolerance to hot-compressed water-treated cellulose and glycolaldehyde.

  3. USE CELLULOSE FOR CLEANING CONCENTRATED SUGAR SOLUTIONS

    Directory of Open Access Journals (Sweden)

    N. G. Kul’neva

    2015-01-01

    Full Text Available Summary. Producing high quality intermediate products in the boiling-crystallization station is an actual problem of sugar production. In the production of white sugar brown sugar syrup is not further purified that decreases the quality of the end product. Studies have been conducted using cellulose as an adsorbent for the purification of concentrated sugar solutions, having affinity to dyes and other impurities. Research have been carried out with the intermediate products of the Lebedyan sugar plant. Test results have shown cellulose ability to adsorb the dyes in sugar production. The influence of the adsorbent concentration and the mass fraction of solids in the syrup on the decolorization effect has been studied; rational process parameters have been obtained. It has been found that proceeding an additional adsorption purification of brown sugars syrup allows to reduce the solution color, increase the amount and quality of the end product. Adsorbing means, received from production wastes on the basis of organic resources, have many advantages: economical, environmentally friendly for disposal, safe to use, reliable and efficient in use. Conducted research on using cellulose as adsorbent for treatment of concentrated sugar solutions, having an affinity for colouring matter and other impurities. The experiments were carried out on the intermediates Lebedyanskiy sugar factory. The test results showed the ability of cellulose to adsorb coloring matter of sugar production. To evaluate the effect of bleaching depending on the mass fraction of dry substances prepared yellow juice filtration of sugar concentration of 55, 60, 65 % with subsequent adsorption purification of cellulose. The results of the experiment built adsorption isotherm of dyestuffs. The influence of the concentration of the adsorbent and a mass fraction of solids of juice filtration on the efficiency of decolorization obtained by rational parameters of the process. It is

  4. Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase1[OPEN

    Science.gov (United States)

    Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Bulone, Vincent

    2017-01-01

    Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens. Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. PMID:28768815

  5. Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase.

    Science.gov (United States)

    Cho, Sung Hyun; Purushotham, Pallinti; Fang, Chao; Maranas, Cassandra; Díaz-Moreno, Sara M; Bulone, Vincent; Zimmer, Jochen; Kumar, Manish; Nixon, B Tracy

    2017-09-01

    Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual β-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize β-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro- and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins. © 2017 American Society of Plant Biologists. All Rights Reserved.

  6. Ductile all-cellulose nanocomposite films fabricated from core-shell structured cellulose nanofibrils.

    Science.gov (United States)

    Larsson, Per A; Berglund, Lars A; Wågberg, Lars

    2014-06-09

    Cellulosic materials have many desirable properties such as high mechanical strength and low oxygen permeability and will be an important component in a sustainable biomaterial-based society, but unfortunately they often lack the ductility and formability offered by petroleum-based materials. This paper describes the fabrication and characterization of nanocomposite films made of core-shell modified cellulose nanofibrils (CNFs) surrounded by a shell of ductile dialcohol cellulose, created by heterogeneous periodate oxidation followed by borohydride reduction of the native cellulose in the external parts of the individual fibrils. The oxidation with periodate selectively produces dialdehyde cellulose, and the process does not increase the charge density of the material. Yet the modified cellulose fibers could easily be homogenized to CNFs. Prior to film fabrication, the CNF was shown by atomic force microscopy to be 0.5-2 μm long and 4-10 nm wide. The films were fabricated by filtration, and besides uniaxial tensile testing at different relative humidities, they were characterized by scanning electron microscopy and oxygen permeability. The strength-at-break at 23 °C and 50% RH was 175 MPa, and the films could, before rupture, be strained, mainly by plastic deformation, to about 15% and 37% at 50% RH and 90% RH, respectively. This moisture plasticization was further utilized to form a demonstrator consisting of a double-curved structure with a nominal strain of 24% over the curvature. At a relative humidity of 80%, the films still acted as a good oxygen barrier, having an oxygen permeability of 5.5 mL·μL/(m(2)·24 h·kPa). These properties indicate that this new material has a potential for use as a barrier in complex-shaped structures and hence ultimately reduce the need for petroleum-based plastics.

  7. Evaluation of ethanol productivity from cellulose by Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Kurose, N; Yagyu, J; Miyazaki, T; Uchida, M; Hanai, S; Obayashi, A

    1986-01-01

    Clostridium thermocellum, a thermophilic anaerobe, directly converts cellulose to EtOH. To estimate its EtOH production from cellulose, we used a new method based on material balance by which the efficiencies of the enzymes that convert cellulose to ethanol were calculated. Using this method, the maximum efficiency of ethanol production of two strains of C. thermocellum was estimated to be 0.05, with 0.67 as the theoretical maximum. 3 references.

  8. Both solubility and chemical stability of curcumin are enhanced by solid dispersion in cellulose derivative matrices.

    Science.gov (United States)

    Li, Bin; Konecke, Stephanie; Wegiel, Lindsay A; Taylor, Lynne S; Edgar, Kevin J

    2013-10-15

    Amorphous solid dispersions (ASD) of curcumin (Cur) in cellulose derivative matrices, hydroxypropylmethylcellulose acetate succinate (HPMCAS), carboxymethylcellulose acetate butyrate (CMCAB), and cellulose acetate adipate propionate (CAAdP) were prepared in order to investigate the structure-property relationship and identify polymer properties necessary to effectively increase Cur aqueous solution concentration. XRD results indicated that all investigated solid dispersions were amorphous, even at a 9:1 Cur:polymer ratio. Both stability against crystallization and Cur solution concentration from these ASDs were significantly higher than those from physical mixtures and crystalline Cur. Remarkably, curcumin was also stabilized against chemical degradation in solution. Chemical stabilization was polymer-dependent, with stabilization in CAAdP>CMCAB>HPMCAS>PVP, while matrices enhanced solution concentration as PVP>HPMCAS>CMCAB≈CAAdP. HPMCAS/Cur dispersions have useful combinations of pH-triggered release profile, chemical stabilization, and strong enhancement of Cur solution concentration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Morphological and spectroscopic analysis of cellulose nanocrystals extracted from oil palm empty fruit bunch fiber

    Energy Technology Data Exchange (ETDEWEB)

    Dasan, Y. K., E-mail: aamir.bhat@petronas.com.my; Bhat, A. H., E-mail: aamir.bhat@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750, Bandar Seri Iskandar, Perak (Malaysia); Faiz, A., E-mail: faizahmad@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, 31750, Bandar Seri Iskandar, Perak (Malaysia)

    2015-07-22

    This work evaluates the use of oil palm empty fruit bunch (OPEFB) fiber as a source of cellulose to obtain nanocrystalline cellulose (CNC) by acid hydrolysis reaction. The raw OPEFB fibers were pretreated with aqueous Sodium hydroxide at 80°C followed by bleaching treatment and further hydrolyzed with Sulphuric acid at 45°C with limited range of hydrolysis time and acid concentration. The resulting CNC’s were characterized for spectroscopic, crystallographic and morphological properties using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM) and Atomic Force Microscopy (AFM). Finding of this study shows that the properties of CNC’s are strongly dependent on the hydrolysis time and acid concentration.

  10. A synthetic auxin (NAA) suppresses secondary wall cellulose synthesis and enhances elongation in cultured cotton fiber.

    Science.gov (United States)

    Singh, Bir; Cheek, Hannah D; Haigler, Candace H

    2009-07-01

    Use of a synthetic auxin (naphthalene-1-acetic acid, NAA) to start (Gossypium hirsutum) ovule/fiber cultures hindered fiber secondary wall cellulose synthesis compared with natural auxin (indole-3-acetic acid, IAA). In contrast, NAA promoted fiber elongation and ovule weight gain, which resulted in larger ovule/fiber units. To reach these conclusions, fiber and ovule growth parameters were measured and cell wall characteristics were examined microscopically. The differences in fiber from NAA and IAA culture were underpinned by changes in the expression patterns of marker genes for three fiber developmental stages (elongation, the transition stage, and secondary wall deposition), and these gene expression patterns were also analyzed quantitatively in plant-grown fiber. The results demonstrate that secondary wall cellulose synthesis: (1) is under strong transcriptional control that is influenced by auxin; and (2) must be specifically characterized in the cotton ovule/fiber culture system given the many protocol variables employed in different laboratories.

  11. Dispersions of attractive semiflexible fiberlike colloidal particles from bacterial cellulose microfibrils.

    Science.gov (United States)

    Kuijk, Anke; Koppert, Remco; Versluis, Peter; van Dalen, Gerard; Remijn, Caroline; Hazekamp, Johan; Nijsse, Jaap; Velikov, Krassimir P

    2013-11-26

    We prepared dispersions from bacterial cellulose microfibrils (CMF) of a commercial Nata de Coco source. We used an ultra-high-energy mechanical deagglomeration process that is able to disperse the CMFs from the pellicle in which they are organized in an irregular network. Because of the strong attractions between the CMFs, the dispersion remained highly heterogeneous, consisting of fiber bundles, flocs, and voids spanning tens to hundreds of micrometers depending on concentration. The size of these flocs increased with CMF concentration, the size of the bundles stayed constant, and the size of the voids decreased. The observed percolation threshold in MFC dispersions is lower than the theoretical prediction, which is accounted for by the attractive interactions in the system. Because bacterial cellulose is chemically very pure, it can be used to study the interaction of attractive and highly shape-anisotropic, semiflexible fiberlike colloidal particles.

  12. Synthesis of amide-functionalized cellulose esters by olefin cross-metathesis.

    Science.gov (United States)

    Meng, Xiangtao; Edgar, Kevin J

    2015-11-05

    Cellulose esters with amide functionalities were synthesized by cross-metathesis (CM) reaction of terminally olefinic esters with different acrylamides, catalyzed by Hoveyda-Grubbs 2nd generation catalyst. Chelation by amides of the catalyst ruthenium center caused low conversions using conventional solvents. The effects of both solvent and structure of acrylamide on reaction conversion were investigated. While the inherent tendency of acrylamides to chelate Ru is governed by the acrylamide N-substituents, employing acetic acid as a solvent significantly improved the conversion of certain acrylamides, from 50% to up to 99%. Homogeneous hydrogenation using p-toluenesulfonyl hydrazide successfully eliminated the α,β-unsaturation of the CM products to give stable amide-functionalized cellulose esters. The amide-functionalized product showed higher Tg than its starting terminally olefinic counterpart, which may have resulted from strong hydrogen bonding interactions of the amide functional groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yu, Shun; Yan, Min; Berglund, Lars

    2016-04-11

    Optically transparent wood (TW) with transmittance as high as 85% and haze of 71% was obtained using a delignified nanoporous wood template. The template was prepared by removing the light-absorbing lignin component, creating nanoporosity in the wood cell wall. Transparent wood was prepared by successful impregnation of lumen and the nanoscale cellulose fiber network in the cell wall with refractive-index-matched prepolymerized methyl methacrylate (MMA). During the process, the hierarchical wood structure was preserved. Optical properties of TW are tunable by changing the cellulose volume fraction. The synergy between wood and PMMA was observed for mechanical properties. Lightweight and strong transparent wood is a potential candidate for lightweight low-cost, light-transmitting buildings and transparent solar cell windows.

  14. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    Science.gov (United States)

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-08

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Strongly disordered superconductors

    International Nuclear Information System (INIS)

    Muttalib, K.A.

    1982-01-01

    We examine some universal effects of strong non-magnetic disorder on the electron-phonon and electron-electron interactions in a superconductor. In particular we explicitly take into account the effect of slow diffusion of electrons in a disordered medium by working in an exact impurity eigenstate representation. We find that the normal diffusion of electrons characterized by a constant diffusion coefficient does not lead to any significant correction to the electron-phonon or the effective electron-electron interactions in a superconductor. We then consider sufficiently strong disorder where Anderson localization of electrons becomes important and determine the effect of localization on the electron-electron interactions. We find that due to localization, the diffusion of electrons becomes anomalous in the sense that the diffusion coefficient becomes scale dependent. This results in an increase in the effective electron-electron interaction with increasing disorder. We propose that this provides a natural explanation for the unusual sensitivity of the transition temperature T/sub c/ of the high T/sub c/ superconductors (T/sub c/ > 10 0 K) to damage effects

  16. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  17. Impairment of Cellulose Synthases Required for Arabidopsis Secondary Cell Wall Formation Enhances Disease Resistance[W

    Science.gov (United States)

    Hernández-Blanco, Camilo; Feng, Dong Xin; Hu, Jian; Sánchez-Vallet, Andrea; Deslandes, Laurent; Llorente, Francisco; Berrocal-Lobo, Marta; Keller, Harald; Barlet, Xavier; Sánchez-Rodríguez, Clara; Anderson, Lisa K.; Somerville, Shauna; Marco, Yves; Molina, Antonio

    2007-01-01

    Cellulose is synthesized by cellulose synthases (CESAs) contained in plasma membrane–localized complexes. In Arabidopsis thaliana, three types of CESA subunits (CESA4/IRREGULAR XYLEM5 [IRX5], CESA7/IRX3, and CESA8/IRX1) are required for secondary cell wall formation. We report that mutations in these proteins conferred enhanced resistance to the soil-borne bacterium Ralstonia solanacearum and the necrotrophic fungus Plectosphaerella cucumerina. By contrast, susceptibility to these pathogens was not altered in cell wall mutants of primary wall CESA subunits (CESA1, CESA3/ISOXABEN RESISTANT1 [IXR1], and CESA6/IXR2) or POWDERY MILDEW–RESISTANT5 (PMR5) and PMR6 genes. Double mutants indicated that irx-mediated resistance was independent of salicylic acid, ethylene, and jasmonate signaling. Comparative transcriptomic analyses identified a set of common irx upregulated genes, including a number of abscisic acid (ABA)–responsive, defense-related genes encoding antibiotic peptides and enzymes involved in the synthesis and activation of antimicrobial secondary metabolites. These data as well as the increased susceptibility of ABA mutants (abi1-1, abi2-1, and aba1-6) to R. solanacearum support a direct role of ABA in resistance to this pathogen. Our results also indicate that alteration of secondary cell wall integrity by inhibiting cellulose synthesis leads to specific activation of novel defense pathways that contribute to the generation of an antimicrobial-enriched environment hostile to pathogens. PMID:17351116

  18. A multiscale crack-bridging model of cellulose nanopaper

    Science.gov (United States)

    Meng, Qinghua; Li, Bo; Li, Teng; Feng, Xi-Qiao

    2017-06-01

    The conflict between strength and toughness is a long-standing challenge in advanced materials design. Recently, a fundamental bottom-up material design strategy has been demonstrated using cellulose nanopaper to achieve significant simultaneous increase in both strength and toughness. Fertile opportunities of such a design strategy aside, mechanistic understanding is much needed to thoroughly explore its full potential. To this end, here we establish a multiscale crack-bridging model to reveal the toughening mechanisms in cellulose nanopaper. A cohesive law is developed to characterize the interfacial properties between cellulose nanofibrils by considering their hydrogen bonding nature. In the crack-bridging zone, the hydrogen bonds between neighboring cellulose nanofibrils may break and reform at the molecular scale, rendering a superior toughness at the macroscopic scale. It is found that cellulose nanofibrils exhibit a distinct size-dependence in enhancing the fracture toughness of cellulose nanopaper. An optimal range of the length-to-radius ratio of nanofibrils is required to achieve higher fracture toughness of cellulose nanopaper. A unified law is proposed to correlate the fracture toughness of cellulose nanopaper with its microstructure and material parameters. The results obtained from this model agree well with relevant experiments. This work not only helps decipher the fundamental mechanisms underlying the remarkable mechanical properties of cellulose nanopaper but also provides a guide to design a wide range of advanced functional materials.

  19. Cellulosic Fibers: Effect of Processing on Fiber Bundle Strength

    DEFF Research Database (Denmark)

    Thygesen, Anders; Madsen, Bo; Thomsen, Anne Belinda

    2011-01-01

    A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding, and cotto......A range of differently processed cellulosic fibers from flax and hemp plants were investigated to study the relation between processing of cellulosic fibers and fiber bundle strength. The studied processing methods are applied for yarn production and include retting, scutching, carding...

  20. Graft Copolymerization Of Methyl Methacrylate Onto Agave Cellulose

    International Nuclear Information System (INIS)

    Noor Afizah Rosli; Ishak Ahmad; Ibrahim Abdullah; Farah Hannan Anuar

    2014-01-01

    The grafting polymerization of methyl methacrylate (MMA) and Agave cellulose was prepared and the grafting reaction conditions were optimized by varying the reaction time and temperature, and ratio of monomer to cellulose. The resulting graft copolymers were characterized by Fourier transform infrared, X-ray diffraction analysis, thermogravimetric analysis, and scanning electron microscopy (SEM). The experimental results showed that the optimal conditions were at a temperature of 45 degree Celsius for 90 min with ratio monomer to cellulose at 1:1 (g/ g). An additional peak at 1738 cm -1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted cellulose, respectively. Grafting of MMA onto cellulose enhanced its thermal stability and SEM observation further furnished evidence of grafting MMA onto Agave cellulose with increasing cellulose diameter and surface roughness. (author)

  1. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  2. Strongly interacting Higgs bosons

    International Nuclear Information System (INIS)

    Appelquist, T.; Bernard, C.

    1980-01-01

    The sensitivity of present-energy weak interactions to a strongly interacting heavy-Higgs-boson sector is discussed. The gauged nonlinear sigma model, which is the limit of the linear model as the Higgs-boson mass goes to infinity, is used to organize and catalogue all possible heavy-Higgs-boson effects. As long as the SU(2)/sub L/ x SU(2)/sub R/ symmetry of the Higgs sector is preserved, these effects are found to be small, of the order of the square of the gauge coupling times logarithms (but not powers) of the Higgs-boson mass divided by the W mass. We work in the context of a simplified model with gauge group SU(2)/sub L/; the extension to SU(2)/sub L/ x U(1) is briefly discussed

  3. Sticking to cellulose: exploiting Arabidopsis seed coat mucilage to understand cellulose biosynthesis and cell wall polysaccharide interactions.

    Science.gov (United States)

    Griffiths, Jonathan S; North, Helen M

    2017-05-01

    The cell wall defines the shape of cells and ultimately plant architecture. It provides mechanical resistance to osmotic pressure while still being malleable and allowing cells to grow and divide. These properties are determined by the different components of the wall and the interactions between them. The major components of the cell wall are the polysaccharides cellulose, hemicellulose and pectin. Cellulose biosynthesis has been extensively studied in Arabidopsis hypocotyls, and more recently in the mucilage-producing epidermal cells of the seed coat. The latter has emerged as an excellent system to study cellulose biosynthesis and the interactions between cellulose and other cell wall polymers. Here we review some of the major advances in our understanding of cellulose biosynthesis in the seed coat, and how mucilage has aided our understanding of the interactions between cellulose and other cell wall components required for wall cohesion. Recently, 10 genes involved in cellulose or hemicellulose biosynthesis in mucilage have been identified. These discoveries have helped to demonstrate that xylan side-chains on rhamnogalacturonan I act to link this pectin directly to cellulose. We also examine other factors that, either directly or indirectly, influence cellulose organization or crystallization in mucilage. © 2017 INRA. New Phytologist © 2017 New Phytologist Trust.

  4. Reaction kinetics of cellulose hydrolysis in subcritical and supercritical water

    Science.gov (United States)

    Olanrewaju, Kazeem Bode

    The uncertainties in the continuous supply of fossil fuels from the crisis-ridden oil-rich region of the world is fast shifting focus on the need to utilize cellulosic biomass and develop more efficient technologies for its conversion to fuels and chemicals. One such technology is the rapid degradation of cellulose in supercritical water without the need for an enzyme or inorganic catalyst such as acid. This project focused on the study of reaction kinetics of cellulose hydrolysis in subcritical and supercritical water. Cellulose reactions at hydrothermal conditions can proceed via the homogeneous route involving dissolution and hydrolysis or the heterogeneous path of surface hydrolysis. The work is divided into three main parts. First, the detailed kinetic analysis of cellulose reactions in micro- and tubular reactors was conducted. Reaction kinetics models were applied, and kinetics parameters at both subcritical and supercritical conditions were evaluated. The second major task was the evaluation of yields of water soluble hydrolysates obtained from the hydrolysis of cellulose and starch in hydrothermal reactors. Lastly, changes in molecular weight distribution due to hydrothermolytic degradation of cellulose were investigated. These changes were also simulated based on different modes of scission, and the pattern generated from simulation was compared with the distribution pattern from experiments. For a better understanding of the reaction kinetics of cellulose in subcritical and supercritical water, a series of reactions was conducted in the microreactor. Hydrolysis of cellulose was performed at subcritical temperatures ranging from 270 to 340 °C (tau = 0.40--0.88 s). For the dissolution of cellulose, the reaction was conducted at supercritical temperatures ranging from 375 to 395 °C (tau = 0.27--0.44 s). The operating pressure for the reactions at both subcritical and supercritical conditions was 5000 psig. The results show that the rate-limiting step in

  5. Extraction of cellulose microcrystalline from galam wood for biopolymer

    Science.gov (United States)

    Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

    2018-04-01

    Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

  6. Twin carbons: The carbonization of cellulose or carbonized cellulose coated with a conducting polymer, polyaniline

    Czech Academy of Sciences Publication Activity Database

    Bober, Patrycja; Kovářová, Jana; Pfleger, Jiří; Stejskal, Jaroslav; Trchová, Miroslava; Novák, I.; Berek, D.

    2016-01-01

    Roč. 109, November (2016), s. 836-842 ISSN 0008-6223 R&D Projects: GA ČR(CZ) GA13-00270S Institutional support: RVO:61389013 Keywords : cellulose * carbon * polyaniline Subject RIV: CD - Macromolecular Chemistry Impact factor: 6.337, year: 2016

  7. Optimizing cellulose fibrillation for the production of cellulose nanofibrils by a disk grinder

    Science.gov (United States)

    Chuanshuang Hu; Yu Zhao; Kecheng Li; J.Y. Zhu; Roland Gleisner

    2015-01-01

    The fibrillation of a bleached kraft eucalyptus pulp was investigated by means of a laboratory-scale disk grinder for the production of cellulose nanofibrils (CNF), while the parameters disk rotating speed, solid loading, and fibrillation duration were varied. The cumulative energy consumption was monitored during fibrillation. The degree of polymerization (DP) and...

  8. Printed optically transparent graphene cellulose electrodes

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

    2016-02-01

    Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

  9. Atomic-scale modeling of cellulose nanocrystals

    Science.gov (United States)

    Wu, Xiawa

    Cellulose nanocrystals (CNCs), the most abundant nanomaterials in nature, are recognized as one of the most promising candidates to meet the growing demand of green, bio-degradable and sustainable nanomaterials for future applications. CNCs draw significant interest due to their high axial elasticity and low density-elasticity ratio, both of which are extensively researched over the years. In spite of the great potential of CNCs as functional nanoparticles for nanocomposite materials, a fundamental understanding of CNC properties and their role in composite property enhancement is not available. In this work, CNCs are studied using molecular dynamics simulation method to predict their material' behaviors in the nanoscale. (a) Mechanical properties include tensile deformation in the elastic and plastic regions using molecular mechanics, molecular dynamics and nanoindentation methods. This allows comparisons between the methods and closer connectivity to experimental measurement techniques. The elastic moduli in the axial and transverse directions are obtained and the results are found to be in good agreement with previous research. The ultimate properties in plastic deformation are reported for the first time and failure mechanism are analyzed in details. (b) The thermal expansion of CNC crystals and films are studied. It is proposed that CNC film thermal expansion is due primarily to single crystal expansion and CNC-CNC interfacial motion. The relative contributions of inter- and intra-crystal responses to heating are explored. (c) Friction at cellulose-CNCs and diamond-CNCs interfaces is studied. The effects of sliding velocity, normal load, and relative angle between sliding surfaces are predicted. The Cellulose-CNC model is analyzed in terms of hydrogen bonding effect, and the diamond-CNC model compliments some of the discussion of the previous model. In summary, CNC's material properties and molecular models are both studied in this research, contributing to

  10. Cellulose insulation as an air barrier

    Energy Technology Data Exchange (ETDEWEB)

    Manning, K.

    1989-10-01

    The objective of this study was to determine if a wet sprayed cellulose wall insulation system would function satisfactorily without use of a polyethylene air/vapour barrier. The research was designed to demonstrate that this particular insulation system would form enough of a barrier to air leakage, that moisture accumulation from condensation and vapour diffusion would be insignificant. Field work conducted in Alberta, involved construction of a conventional duplex housing unit which was insulated with wet sprayed cellulose in the exterior walls and dry loose-fill cellulose in the attic areas. One half of the unit did not have a polyethylene air/vapor barrier installed. Air leakage and exterior wall moisture levels were monitored for a year following construction. Data collected during this time indicated that the moisture added to the walls during the insulating process was dissipated over the study period. The presence of polyethylene sheeting had no significant effect on the moisture levels in either the wall or attic areas of the test structure. On the other hand, testing indicated that the use of polyethylene sheeting in the wall system did serve to improve blower door air test results. In conclusion, although the air leakage resistance apparently provided by the polyethylene sheeting is significant, the amount is probably not more than could otherwise be obtained by more careful attention to sealing procedures such as those used in the airtight drywall technique. A more important finding is that the use of polyethylene sheeting is not essential in a structure which has the degree of air leakage resistance provided by the insulation system used in this project. 6 figs., 2 tabs.

  11. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  12. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  13. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  14. Coarse-grained model for the interconversion between different crystalline cellulose allomorphs

    Energy Technology Data Exchange (ETDEWEB)

    Langan, Paul [ORNL

    2012-01-01

    We present the results of Langevin dynamics simulations on a coarse grained model for crystalline cellulose. In particular, we analyze two different cellulose crystalline forms: cellulose I (the natural form of cellulose) and cellulose IIII (obtained after cellulose I is treated with anhydrous liquid ammonia). Cellulose IIII has been the focus of wide interest in the field of cellulosic biofuels as it can be efficiently hydrolyzed to glucose (its enzymatic degradation rates are up to 5 fold higher than those of cellulose I ). In turn, glucose can eventually be fermented into fuels. The coarse-grained model presented in this study is based on a simplified geometry and on an effective potential mimicking the changes in both intracrystalline hydrogen bonds and stacking interactions during the transition from cellulose I to cellulose IIII. The model accurately reproduces both structural and thermomechanical properties of cellulose I and IIII. The work presented herein describes the structural transition from cellulose I to cellulose IIII as driven by the change in the equilibrium state of two degrees of freedom in the cellulose chains. The structural transition from cellulose I to cellulose IIII is essentially reduced to a search for optimal spatial arrangement of the cellulose chains.

  15. Carbon materials derived from chitosan/cellulose cryogel-supported zeolite imidazole frameworks for potential supercapacitor application.

    Science.gov (United States)

    Li, Zehui; Yang, Lan; Cao, Hongbin; Chang, Yu; Tang, Kexin; Cao, Zhiqin; Chang, Junjun; Cao, Youpeng; Wang, Wenbo; Gao, Meng; Liu, Chenming; Liu, Dagang; Zhao, He; Zhang, Yi; Li, Mingjie

    2017-11-01

    In order to promote sustainable development, green and renewable clean energy technologies continue to be developed to meet the growing demand for energy, such as supercapacitor, fuel cells and lithium-ion battery. It is urgent to develop appropriate nanomaterials for these energy technologies to reduce the volume of the device, improve the efficiency of energy conversion and enlarge the energy storage capacity. Here, chitosan/cellulose carbon cryogel (CCS/CCL) were designed and synthesized. Through the introduction of zeolite imidazole frameworks (ZIFs) into the chitosan/cellulose cryogels, the obtained materials showed a microstructure of ZIF-7 (a kind of ZIFs) coated chitosan/cellulose fibers (CS/CL). After carbonizing, the as-prepared carbonized ZIF-7@cellulose cryogel (NC@CCL, NC is carbonized ZIF-7) and carbonized ZIF-7@chitosan cryogel (NC@CCS) exhibited suitable microspore contents of 34.37% and 30%, respectively, and they both showed an internal resistance lower than 2Ω. Thereby, NC@CCL and NC@CCS exhibited a high specific capacitance of 150.4Fg -1 and 173.1Fg -1 , respectively, which were much higher than those of the original materials. This approach offers a facile method for improving the strength and electronic conductivity of carbon cryogel derived from nature polymers, and also efficiently inhibits the agglomeration of cryogel during carbonization in high temperature, which opens a novel avenue for the development of carbon cryogel materials for application in energy conversion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The FPase properties and morphology changes of a cellulolytic bacterium, Sporocytophaga sp. JL-01, on decomposing filter paper cellulose.

    Science.gov (United States)

    Wang, Xiuran; Peng, Zhongqi; Sun, Xiaoling; Liu, Dongbo; Chen, Shan; Li, Fan; Xia, Hongmei; Lu, Tiancheng

    2012-01-01

    Sporocytophaga sp. JL-01 is a sliding cellulose degrading bacterium that can decompose filter paper (FP), carboxymethyl cellulose (CMC) and cellulose CF11. In this paper, the morphological characteristics of S. sp. JL-01 growing in FP liquid medium was studied by Scanning Electron Microscope (SEM), and one of the FPase components of this bacterium was analyzed. The results showed that the cell shapes were variable during the process of filter paper cellulose decomposition and the rod shape might be connected with filter paper decomposing. After incubating for 120 h, the filter paper was decomposed significantly, and it was degraded absolutely within 144 h. An FPase1 was purified from the supernatant and its characteristics were analyzed. The molecular weight of the FPase1 was 55 kDa. The optimum pH was pH 7.2 and optimum temperature was 50°C under experiment conditions. Zn(2+) and Co(2+) enhanced the enzyme activity, but Fe(3+) inhibited it.

  17. Cellulose decomposition in a 50 MVA transformer

    International Nuclear Information System (INIS)

    Piechalak, B.W.

    1992-01-01

    Dissolved gas-in-oil analysis for carbon monoxide and carbon dioxide has been used for years to predict cellulose decomposition in a transformer. However, the levels at which these gases become significant have not been widely agreed upon. This paper evaluates the gas analysis results from the nitrogen blanket and the oil of a 50 MVA unit auxiliary transformer in terms of whether accelerated thermal breakdown or normal aging of the paper is occurring. Furthermore, this paper presents additional data on carbon monoxide and carbon dioxide levels in unit and system auxiliary transformers at generating stations and explains why their levels differ

  18. A Sorption Hysteresis Model For Cellulosic Materials

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Damkilde, Lars

    2006-01-01

    The equilibrium concentration of adsorbed water in cellulosic materials is dependent on the history of the variations of vapor pressure in the ambient air, i.e. sorption hysteresis. Existing models to describe this phenomenon such as the independent domain theory have numerical drawbacks and....../or imply accounting for the entire history variations of every material point. This paper presents a sorption hysteresis model based on a state formulation and expressed in closed-form solutions, which makes it suitable for implementation into a numerical method....

  19. Ultrasound-assisted swelling of bacterial cellulose

    OpenAIRE

    Song, J.; Su, Jing; Loureiro, Ana; Sá, M.; Cavaco-Paulo, Artur; Kim, Hye Rim; Silva, Carla

    2017-01-01

    Bacterial cellulose (BC) was obtained by static cultivation using commercial BC gel from scoby. BC membranes (oven dried and freeze-dried) were swelled with 8% NaOH, in absence and in presence of ultrasound (US), for 30, 60 and 90 min. The influence of swelling conditions on both physico-chemical properties and molecules entrapment was evaluated. Considering the highest levels of entrapment, an optimum swelling procedure was established: 8% NaOH for 30 min. at room temperature in the presence...

  20. Nanocoating cellulose paper based microextraction combined with nanospray mass spectrometry for rapid and facile quantitation of ribonucleosides in human urine.

    Science.gov (United States)

    Wan, Lingzhong; Zhu, Haijing; Guan, Yafeng; Huang, Guangming

    2017-07-01

    A rapid and facile analytical method for quantification of ribonucleosides in human urine was developed by the combination of nanocoating cellulose paper based microextraction and nanoelectrospray ionization-tandem mass spectrometry (nESI-MS/MS). Cellulose paper used for microextraction was modified by nano-precision deposition of uniform ultrathin zirconia gel film using a sol-gel process. Due to the large surface area of the cellulose paper and the strong affinity between zirconia and the cis-diol compounds, the target analytes were selectively extracted from the complex matrix. Thus, the detection sensitivity was greatly improved. Typically, the nanocoating cellulose paper was immersed into the diluted urine for selective extraction of target analytes, then the extracted analytes were subjected to nESI-MS/MS detection. The whole analytical procedure could be completed within 10min. The method was evaluated by the determination of ribonucleosides (adenosine, cytidine, uridine, guanosine) in urine sample. The signal intensities of the ribonuclesides extracted by the nanocoating cellulose paper were greatly enhanced by 136-459-folds compared with the one of the unmodified cellulose paper based microextraction. The limits of detection (LODs) and the limits of quantification (LOQs) of the four ribonucleosides were in the range of 0.0136-1.258μgL -1 and 0.0454-4.194μgL -1 , respectively. The recoveries of the target nucleosides from spiked human urine were in the range of 75.64-103.49% with the relative standard deviations (RSDs) less than 9.36%. The results demonstrate the potential of the proposed method for rapid and facile determination of endogenous ribonucleosides in urine sample. Copyright © 2017. Published by Elsevier B.V.

  1. Evolving Microbial Communities in Cellulose-Fed Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Renata Toczyłowska-Mamińska

    2018-01-01

    Full Text Available The abundance of cellulosic wastes make them attractive source of energy for producing electricity in microbial fuel cells (MFCs. However, electricity production from cellulose requires obligate anaerobes that can degrade cellulose and transfer electrons to the electrode (exoelectrogens, and thus most previous MFC studies have been conducted using two-chamber systems to avoid oxygen contamination of the anode. Single-chamber, air-cathode MFCs typically produce higher power densities than aqueous catholyte MFCs and avoid energy input for the cathodic reaction. To better understand the bacterial communities that evolve in single-chamber air-cathode MFCs fed cellulose, we examined the changes in the bacterial consortium in an MFC fed cellulose over time. The most predominant bacteria shown to be capable electron generation was Firmicutes, with the fermenters decomposing cellulose Bacteroidetes. The main genera developed after extended operation of the cellulose-fed MFC were cellulolytic strains, fermenters and electrogens that included: Parabacteroides, Proteiniphilum, Catonella and Clostridium. These results demonstrate that different communities evolve in air-cathode MFCs fed cellulose than the previous two-chamber reactors.

  2. Films based on oxidized starch and cellulose from barley.

    Science.gov (United States)

    El Halal, Shanise Lisie Mello; Colussi, Rosana; Deon, Vinícius Gonçalves; Pinto, Vânia Zanella; Villanova, Franciene Almeida; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2015-11-20

    Starch and cellulose fibers were isolated from grains and the husk from barley, respectively. Biodegradable films of native starch or oxidized starches and glycerol with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. Cellulose fibers isolated from the barley husk were obtained with 75% purity and high crystallinity. The morphology of the films of the oxidized starches, regardless of the fiber addition, was more homogeneous as compared to the film of the native starch. The addition of cellulose fibers in the films increased the tensile strength and decreased elongation. The water vapor permeability of the film of oxidized starch with 20% of cellulose fibers was lower than the without fibers. However the films with cellulose fibers had the highest decomposition with the initial temperature and thermal stability. The oxidized starch and cellulose fibers from barley have a good potential for use in packaging. The addition of cellulose fibers in starch films can contribute to the development of films more resistant that can be applied in food systems to maintain its integrity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of antimicrobial agents on cellulose acetate nano composites properties

    International Nuclear Information System (INIS)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo

    2011-01-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  4. Methods of use of cellulose binding domain proteins

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1997-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  5. Methods of detection using a cellulose binding domain fusion product

    Science.gov (United States)

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1999-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  6. Cellulose microfibril deposition: coordinated activity at the plant plasma membrane

    NARCIS (Netherlands)

    Lindeboom, J.J.; Mulder, B.; Vos, J.W.; Ketelaar, M.J.; Emons, A.M.C.

    2008-01-01

    Plant cell wall production is a membrane-bound process. Cell walls are composed of cellulose microfibrils, embedded inside a matrix of other polysaccharides and glycoproteins. The cell wall matrix is extruded into the existing cell wall by exocytosis. This same process also inserts the cellulose

  7. Dual morphology (fibres and particles) cellulosic filler for WPC materials

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Marco, E-mail: marco.valente@uniroma1.it; Tirillò, Jacopo; Quitadamo, Alessia, E-mail: alessia.quitadamo@uniroma1.it [University of Rome La Sapienza Dep. of Chemical and Material Engineering (Italy); Santulli, Carlo [University of Camerino, School of Architecture and Design (Italy)

    2016-05-18

    Wood-plastic composites (WPC) were fabricated by using a polyethylene (PE) matrix and filling it with wood flour in the amount of 30 wt.%, and compared with the same composites with further amount of 10 wt.% of cellulosic recycled fibres added. The materials were produced by turbomixing and subsequent moulding under pressure. Mechanical properties of both WPC and WPC with cellulosic recycled fibres were evaluated through mechanical and physical-chemical tests. Tensile tests clarified that a moderate reduction is strength is observed with the bare introduction of wood flour with respect to the neat PE matrix, whilst some recovery is offered by the addition of recycled cellulose fibres. Even more promisingly, the elastic modulus of PE matrix is substantially improved by the addition of wood flour (around 8% on average) and much more so with the further addition of recycled cellulose (around 20% on average). The fracture surfaces from the tensile test were analysed by scanning electron microscope (SEM) indicating a reduction in microporosity as an effect of added cellulose. The water absorption test and the hardness measure (Shore D) were also performed. SEM analysis underlined the weak interface between both wood particle and cellulosic recycled fibres and matrix. The water absorption test showed a higher mass variation for pure WPC than WPC with cellulosic recycled fibres. The hardness measurement showed that the presence of cellulosic recycled fibres improves both superficial hardness of the composite and temperature resistance.

  8. Dual morphology (fibres and particles) cellulosic filler for WPC materials

    International Nuclear Information System (INIS)

    Valente, Marco; Tirillò, Jacopo; Quitadamo, Alessia; Santulli, Carlo

    2016-01-01

    Wood-plastic composites (WPC) were fabricated by using a polyethylene (PE) matrix and filling it with wood flour in the amount of 30 wt.%, and compared with the same composites with further amount of 10 wt.% of cellulosic recycled fibres added. The materials were produced by turbomixing and subsequent moulding under pressure. Mechanical properties of both WPC and WPC with cellulosic recycled fibres were evaluated through mechanical and physical-chemical tests. Tensile tests clarified that a moderate reduction is strength is observed with the bare introduction of wood flour with respect to the neat PE matrix, whilst some recovery is offered by the addition of recycled cellulose fibres. Even more promisingly, the elastic modulus of PE matrix is substantially improved by the addition of wood flour (around 8% on average) and much more so with the further addition of recycled cellulose (around 20% on average). The fracture surfaces from the tensile test were analysed by scanning electron microscope (SEM) indicating a reduction in microporosity as an effect of added cellulose. The water absorption test and the hardness measure (Shore D) were also performed. SEM analysis underlined the weak interface between both wood particle and cellulosic recycled fibres and matrix. The water absorption test showed a higher mass variation for pure WPC than WPC with cellulosic recycled fibres. The hardness measurement showed that the presence of cellulosic recycled fibres improves both superficial hardness of the composite and temperature resistance.

  9. Addressing Cellulose Acetate Microfilm from a British Library perspective

    Directory of Open Access Journals (Sweden)

    Helen Shenton

    2005-08-01

    Full Text Available This paper is about cellulose acetate microfilm from the British Library perspective. It traces how acetate microfilm became an issue for the British Library and describes cellulose acetate deterioration. This is followed by details of what has already been done about the situation and what action is planned for the future.

  10. Life Cycle Assessment of man-made cellulose fibres

    NARCIS (Netherlands)

    Shen, L.; Patel, M.K.

    2010-01-01

    The production of textile materials has undergone dramatic changes in the last century. Man-made cellulose fibres have played an important role for more than 70 years. Today, the man-made cellulose fibre industry is the worldwide second largest biorefinery (next to the paper industry). In the last

  11. Nanoreinforced biocompatible hydrogels from wood hemicelluloses and cellulose whiskers

    Science.gov (United States)

    Muzaffer Ahmet Karaaslan; Mandla A. Tshabalala; Daniel J. Yelle; Gisela Buschle-Diller

    2011-01-01

    Nanoreinforced hydrogels with a unique network structure were prepared from wood cellulose whiskers coated with chemically modified wood hemicelluloses. The hemicelluloses were modified with 2-hydroxyethylmethacrylate prior to adsorption onto the cellulose whiskers in aqueous medium. Synthesis of the hydrogels was accomplished by in situ radical polymerization of the...

  12. Effect of antimicrobial agents on cellulose acetate nano composites properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Francisco J.; Bruna, Julio E.; Galotto, Maria J.; Guarda, Abel; Sepulveda, Hugo, E-mail: francisco.rodriguez.m@usach.cl [Center for the Development of Nanoscience and Nanotechnology (CEDENNA). Universidad de Santiago de Chile. Faculty of Technology. Department of Food Science and Technology. Food Packaging Laboratory. Santiago (Chile)

    2011-07-01

    Nano composites based on cellulose acetate, Cloisite 30B, triethyl citrate and thymol or cinnamaldehyde were prepared using a dissolution casting technique. The effect of thymol and cinnamaldehyde on the cellulose acetate nano composite properties was evaluated by XRD and DSC. Important changes on the thermal properties and morphological structure were observed according to thymol and cinnamaldehyde content. (author)

  13. Environmental impact assessment of man-made cellulose fibres

    NARCIS (Netherlands)

    Shen, L.; Worrell, E.; Patel, M.K.

    2010-01-01

    Man-made cellulose fibres have played an important role in the production of textile products for more than 70 years. The purpose of this study is to assess the environmental impact of man-made cellulose fibres. Life cycle assessment (LCA) was conducted for three types of fibres (i.e. Viscose, Modal

  14. Hydration Control of the Mechanical and Dynamical Properties of Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Petridis, Loukas; O’Neill, Hugh M.; Johnsen, Mariah [Ripon College, Ripon, Wisconsin 54971, United States; Fan, Bingxin [Department; Schulz, Roland [Department; Mamontov, Eugene; Maranas, Janna [Department; Langan, Paul [Department; Smith, Jeremy C. [Department

    2014-10-13

    The mechanical and dynamical properties of cellulose, the most abundant biomolecule on earth, are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-time scale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ~240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation, 20% hydrated cellulose is more rigid than the dry form, due to more closely packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here describes how hydration-dependent increased fluctuations and hydroxymethyl disorder at the cellulose surface lead to enhancement of the rigidity of this important biomolecule.

  15. Endurance of high molecular weight carboxymethyl cellulose in corrosive environments

    Science.gov (United States)

    Murodov, M. M.; Rahmanberdiev, G. R.; Khalikov, M. M.; Egamberdiev, E. A.; Negmatova, K. C.; Saidov, M. M.; Mahmudova, N.

    2012-07-01

    Lignin obtained from the waste cooking liquor, formed after soda pulping process, is used as an inhibitor of NaCMC thermo oxidative degradation in presence of in extreme conditions during drilling oil wells. In this paper the schematic process of obtaining NaCMC by the principle of "monoapparat" on the basis of cellulose produced by non-wood cellulose materials is presented.

  16. Cellulose nanomaterials as green nanoreinforcements for polymer nanocomposites

    Science.gov (United States)

    Dufresne, Alain

    2017-12-01

    Unexpected and attractive properties can be observed when decreasing the size of a material down to the nanoscale. Cellulose is no exception to the rule. In addition, the highly reactive surface of cellulose resulting from the high density of hydroxyl groups is exacerbated at this scale. Different forms of cellulose nanomaterials, resulting from a top-down deconstruction strategy (cellulose nanocrystals, cellulose nanofibrils) or bottom-up strategy (bacterial cellulose), are potentially useful for a large number of industrial applications. These include the paper and cardboard industry, use as reinforcing filler in polymer nanocomposites, the basis for low-density foams, additives in adhesives and paints, as well as a wide variety of filtration, electronic, food, hygiene, cosmetic and medical products. This paper focuses on the use of cellulose nanomaterials as a filler for the preparation of polymer nanocomposites. Impressive mechanical properties can be obtained for these materials. They obviously depend on the type of nanomaterial used, but the crucial point is the processing technique. The emphasis is on the melt processing of such nanocomposite materials, which has not yet been properly resolved and remains a challenge. This article is part of a discussion meeting issue `New horizons for cellulose nanotechnology'.

  17. Applications of bacterial cellulose and its composites in biomedicine.

    Science.gov (United States)

    Rajwade, J M; Paknikar, K M; Kumbhar, J V

    2015-03-01

    Bacterial cellulose produced by few but specific microbial genera is an extremely pure natural exopolysaccharide. Besides providing adhesive properties and a competitive advantage to the cellulose over-producer, bacterial cellulose confers UV protection, ensures maintenance of an aerobic environment, retains moisture, protects against heavy metal stress, etc. This unique nanostructured matrix is being widely explored for various medical and nonmedical applications. It can be produced in various shapes and forms because of which it finds varied uses in biomedicine. The attributes of bacterial cellulose such as biocompatibility, haemocompatibility, mechanical strength, microporosity and biodegradability with its unique surface chemistry make it ideally suited for a plethora of biomedical applications. This review highlights these qualities of bacterial cellulose in detail with emphasis on reports that prove its utility in biomedicine. It also gives an in-depth account of various biomedical applications ranging from implants and scaffolds for tissue engineering, carriers for drug delivery, wound-dressing materials, etc. that are reported until date. Besides, perspectives on limitations of commercialisation of bacterial cellulose have been presented. This review is also an update on the variety of low-cost substrates used for production of bacterial cellulose and its nonmedical applications and includes patents and commercial products based on bacterial cellulose.

  18. Determination of cellulose I crystallinity by FT-Raman spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Richard S. Reiner; Sally A. Ralph

    2009-01-01

    Two new methods based on FT-Raman spectroscopy, one simple, based on band intensity ratio, and the other, using a partial least-squares (PLS) regression model, are proposed to determine cellulose I crystallinity. In the simple method, crystallinity in semicrystalline cellulose I samples was determined based on univariate regression that was first developed using the...

  19. Cellulose nanocrystals from acacia bark-Influence of solvent extraction.

    Science.gov (United States)

    Taflick, Ticiane; Schwendler, Luana A; Rosa, Simone M L; Bica, Clara I D; Nachtigall, Sônia M B

    2017-08-01

    The isolation of cellulose nanocrystals from different lignocellulosic materials has shown increased interest in academic and technological research. These materials have excellent mechanical properties and can be used as nanofillers for polymer composites as well as transparent films for various applications. In this work, cellulose isolation was performed following an environmental friendly procedure without chlorine. Cellulose nanocrystals were isolated from the exhausted acacia bark (after the industrial process of extracting tannin) with the objective of evaluating the effect of the solvent extraction steps on the characteristics of cellulose and cellulose nanocrystals. It was also assessed the effect of acid hydrolysis time on the thermal stability, morphology and size of the nanocrystals, through TGA, TEM and light scattering analyses. It was concluded that the extraction step with solvents was important in the isolation of cellulose, but irrelevant in the isolation of cellulose nanocrystals. Light scattering experiments indicated that 30min of hydrolysis was long enough for the isolation of cellulose nanocrystals. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Assessment of Quality Characteristics of Cellulose, Sheep and Goat ...

    African Journals Online (AJOL)

    Small intestines of 12 West African Dwarf (WAD) sheep and those of 12 Red Sokoto goats obtained from an abattoir were converted into casings. The imported cellulose casing used for the study was obtained from a sausage manufacturing company. Cellulose casing had the widest diameter of 35.00mm followed by ...

  1. Direct compression properties of microcrystalline cellulose and its ...

    African Journals Online (AJOL)

    The influence of silicified microcrystalline cellulose (SMCC) on the flow, compaction and tableting properties of metronidazole powder was investigated. The study compared medium grades of both SMCC and standard microcrystalline cellulose (MCC) as direct compressible excipients. The bulk densities, Hausner quotient ...

  2. Calculation of single chain cellulose elasticity using fully atomistic modeling

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2011-01-01

    Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...

  3. Atomistic Simulation of Frictional Sliding Between Cellulose Iß Nanocrystals

    Science.gov (United States)

    Xiawa Wu; Robert J. Moon; Ashlie Martini

    2013-01-01

    Sliding friction between cellulose Iß nanocrystals is studied using molecular dynamics simulation. The effects of sliding velocity, normal load, and relative angle between sliding surface are predicted, and the results analyzed in terms of the number of hydrogen bonds within and between the cellulose chains. We find that although the observed friction trends can be...

  4. Water Resources Implications of Cellulosic Biofuel Production at a Regional Scale

    Science.gov (United States)

    Christopher, S. F.; Schoenholtz, S. H.; Nettles, J. E.

    2011-12-01

    Recent increases in oil prices, a strong national interest in greater energy independence, and a concern for the role of fossil fuels in global climate change, have led to a dramatic expansion in use of alternative renewable energy sources in the U.S. The U.S. government has mandated production of 36 billion gallons of renewable fuels by 2022, of which 16 billion gallons are required to be cellulosic biofuels. Production of cellulosic biomass offers a promising alternative to corn-based systems because large-scale production of corn-based ethanol often requires irrigation and is associated with increased erosion, excess sediment export, and enhanced leaching of nitrogen and phosphorus. Although cultivation of switchgrass using standard agricultural practices is one option being considered for production of cellulosic biomass, intercropping cellulosic biofuel crops within managed forests could provide feedstock without primary land use change or the water quality impacts associated with annual crops. Catchlight Energy LLC is examining the feasibility and sustainability of intercropping switchgrass in loblolly pine plantations in the southeastern U.S. Ongoing research is determining efficient operational techniques and information needed to evaluate effects of these practices on water resources in small watershed-scale (~25 ha) studies. Three sets of four to five sub-watersheds are fully instrumented and currently collecting calibration data in North Carolina, Alabama, and Mississippi. These watershed studies will provide detailed information to understand processes and guide management decisions. However, environmental implications of cellulosic systems need to be examined at a regional scale. We used the Soil Water Assessment Tool (SWAT), a physically-based hydrologic model, to examine water quantity effects of various land use change scenarios ranging from switchgrass intercropping a small percentage of managed pine forest land to conversion of all managed

  5. High pressure HC1 conversion of cellulose to glucose

    Energy Technology Data Exchange (ETDEWEB)

    Antonoplis, Robert Alexander [Univ. of California, Berkeley, CA (United States); Blanch, Harvey W. [Univ. of California, Berkeley, CA (United States); Wilke, Charles R. [Univ. of California, Berkeley, CA (United States)

    1981-08-01

    The production of ethanol from glucose by means of fermentation represents a potential long-range alternative to oil for use as a transportation fuel. Today's rising oil prices and the dwindling world supply of oil have made other fuels, such as ethanol, attractive alternatives. It has been shown that automobiles can operate, with minor alterations, on a 10% ethanol-gasoline mixture popularly known as gasohol. Wood has long been known as a potential source of glucose. Glucose may be obtained from wood following acid hydrolysis. In this research, it was found that saturating wood particles with HCl gas under pressure was an effective pretreatment before subjecting the wood to dilute acid hydrolysis. The pretreatment is necessary because of the tight lattice structure of cellulose, which inhibits dilute acid hydrolysis. HCl gas makes the cellulose more susceptible to hydrolysis and the glucose yield is doubled when dilute acid hydrolysis is preceded by HCl saturation at high pressure. The saturation was most effectively performed in a fluidized bed reactor, with pure HCl gas fluidizing equal volumes of ground wood and inert particles. The fluidized bed effectively dissipated the large amount of heat released upon HCl absorption into the wood. Batch reaction times of one hour at 314.7 p.s.i.a. gave glucose yields of 80% and xylose yields of 95% after dilute acid hydrolysis. A non-catalytic gas-solid reaction model, with gas diffusing through the solid limiting the reaction rate, was found to describe the HCl-wood reaction in the fluidized bed. HCl was found to form a stable adduct with the lignin residue in the wood, in a ratio of 3.33 moles per mole of lignin monomer. This resulted in a loss of 0.1453 lb. of HCl per pound of wood. The adduct was broken upon the addition of water. A process design and economic evaluation for a plant to produce 214 tons per day of glucose from air-dried ground Populus tristi gave an estimated glucose cost of 15.14 cents per pound

  6. Dissolution of cellulose in ionic liquid: A review

    Science.gov (United States)

    Mohd, N.; Draman, S. F. S.; Salleh, M. S. N.; Yusof, N. B.

    2017-02-01

    Dissolution of cellulose with ionic liquids (IL) and deep eutectic solvent (DES) lets the comprehensive dissolution of cellulose. Basically, cellulose can be dissolved, in some hydrophilic ionic liquids, such as 1-butyl-3-methylimidazolium chloride (BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). Chloride based ionic liquids are suitable solvents for cellulose dissolution. Although the ILs is very useful in fine chemical industry, its application in the pharmaceutical and food industry have been very limited due to issues with toxicity, purity, and high cost. Seeing to these limitations, new green alternative solvent which is DES was used. This green solvents, may be definitely treated as the next-generation reagents for more sustainable industrial development. Thus, this review aims to discuss the dissolution of cellulose either with ionic liquids or DES and its application.

  7. Cellulose-reinforced composites: from micro-to nanoscale

    Directory of Open Access Journals (Sweden)

    Alain Dufresne

    2013-01-01

    Full Text Available This paper present the most relevant advances in the fields of: i cellulose fibres surface modification; ii cellulose fibres-based composite materials; and iii nanocomposites based on cellulose whiskers or starch platelet-like nanoparticles. The real breakthroughs achieved in the first topic concern the use of solvent-free grafting process (plasma and the grafting of the matrix at the surface of cellulose fibres through isocyanate-mediated grafting or thanks to "click chemistry". Concerning the second topic, it is worth to mention that for some cellulose/matrix combination and in the presence of adequate aids or specific surface treatment, high performance composite materials could be obtained. Finally, nanocomposites allow using the semi-crystalline nature and hierarchical structure of lignocellulosic fibres and starch granules to more deeply achieve this goal profitably exploited by Mother Nature

  8. NANOCOMPOSITES OF POLY(LACTIC ACID REINFORCED WITH CELLULOSE NANOFIBRILS

    Directory of Open Access Journals (Sweden)

    Liping Zhang

    2010-06-01

    Full Text Available A chemo-mechanical method was used to prepare cellulose nanofibrils dispersed uniformly in an organic solvent. Poly(ethylene glycol (PEG 1000 was added to the matrix as a compatibilizer to improve the interfacial interaction between the hydrophobic poly(lactic acid (PLA and the hydrophilic cellulose nanofibrils. The composites obtained by solvent casting methods from N,N-Dimethylacetamide (DMAc were characterized by tensile testing machine, atomic force microscope (AFM, scanning electron microscope (SEM, and Fourier transform infrared spectroscopy (FT-IR. The tensile test results indicated that, by adding PEG to the PLA and the cellulose nanofibrils matrix, the tensile strength and the elongation rate increased by 56.7% and 60%, respectively, compared with the PLA/cellulose nanofibrils composites. The FT-IR analysis successfully showed that PEG improved the intermolecular interaction, which is based on the existence of inter-molecular hydrogen bonding among PLA, PEG, and cellulose nanofibrils.

  9. 2, 3-Dihydrazone cellulose: Prospective material for tissue engineering scaffolds

    International Nuclear Information System (INIS)

    Verma, Vipin; Verma, Poonam; Ray, Pratima; Ray, Alok R.

    2008-01-01

    Cellulose was oxidized by sodium metaperiodate to give rise to 2, 3-dialdehyde cellulose with 92% oxidation ratio, which was further reacted with hydrazine to form 2, 3-dihydrazone cellulose for the incorporation of NH 2 groups. Two forms of matrix, i.e. films and sponges were fabricated. The materials were characterized by FTIR spectroscopy. Scanning electron microscopy revealed its porous architecture with an average pore size of 150 μm. Swelling studies were carried out in phosphate buffer saline (PBS) at physiological pH 7.4. The contact angle of the 2, 3-dihydrazone cellulose surface was determined for assessing its hydrophilicity which came out to be 23 deg. ± 2 deg. NIH3T3 mice fibroblast cells were used for determining the cytocompatibility of the surfaces. The morphology of the cells was observed through optical inverted microscopy. The results show that 2, 3-dihydrazone cellulose can be used as scaffold material in tissue engineering

  10. Biofunctional paper via the covalent modification of cellulose.

    Science.gov (United States)

    Yu, Arthur; Shang, Jing; Cheng, Fang; Paik, Bradford A; Kaplan, Justin M; Andrade, Rodrigo B; Ratner, Daniel M

    2012-07-31

    Paper-based analytical devices are the subject of growing interest for the development of low-cost point-of-care diagnostics, environmental monitoring technologies, and research tools for limited-resource settings. However, there are limited chemistries available for the conjugation of biomolecules to cellulose for use in biomedical applications. Herein, divinyl sulfone (DVS) chemistry was demonstrated to immobilize small molecules, proteins, and DNA covalently onto the hydroxyl groups of cellulose membranes through nucleophilic addition. Assays on modified cellulose using protein-carbohydrate and protein-glycoprotein interactions as well as oligonucleotide hybridization showed that the membrane's bioactivity was specific, dose-dependent, and stable over a long period of time. The use of an inkjet printer to form patterns of biomolecules on DVS-activated cellulose illustrates the adaptability of the DVS functionalization technique to pattern sophisticated designs, with potential applications in cellulose-based lateral flow devices.

  11. Environmentally friendly cellulose-based polyelectrolytes in wastewater treatment.

    Science.gov (United States)

    Grenda, Kinga; Arnold, Julien; Gamelas, José A F; Rasteiro, Maria G

    2017-09-01

    Natural-based polyelectrolytes (PELs), with all the advantages coming from being produced from renewable and biodegradable sources, are a potential solution for the removal of dyes from wastewater. In this work, surplus Eucalyptus bleached cellulose fibres from a paper mill were modified to increase the charge and solubility of cellulose. First, reactive aldehyde groups were introduced in the cellulose backbone by periodate oxidation of cellulose. Further modification with alkylammonium produced positively charged cellulose-based PELs. The final products were characterized by several analytical techniques. The PEL with the highest substitution degree of cationic groups was evaluated for its performance in decolouration processes, bentonite being used as aid. This was found to be effective for colour removal of either anionic or cationic dyes. Bio-PELs can thus be considered as very favourable eco-friendly flocculation agents for decolouration of harsh effluents from several industries, considering their biodegradable nature and thus the ability to produce less sludge.

  12. Physical properties of agave cellulose graft polymethyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan [Polymer Research Centre (PORCE), School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor (Malaysia)

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  13. Regulation of cellulose synthesis in response to stress.

    Science.gov (United States)

    Kesten, Christopher; Menna, Alexandra; Sánchez-Rodríguez, Clara

    2017-12-01

    The cell wall is a complex polysaccharide network that provides stability and protection to the plant and is one of the first layers of biotic and abiotic stimuli perception. A controlled remodeling of the primary cell wall is essential for the plant to adapt its growth to environmental stresses. Cellulose, the main component of plant cell walls is synthesized by plasma membrane-localized cellulose synthases moving along cortical microtubule tracks. Recent advancements demonstrate a tight regulation of cellulose synthesis at the primary cell wall by phytohormone networks. Stress-induced perturbations at the cell wall that modify cellulose synthesis and microtubule arrangement activate similar phytohormone-based stress response pathways. The integration of stress perception at the primary cell wall and downstream responses are likely to be tightly regulated by phytohormone signaling pathways in the context of cellulose synthesis and microtubule arrangement. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Evaluation of supercritical CO2 dried cellulose aerogels as nano-biomaterials

    Science.gov (United States)

    Lee, Sinah; Kang, Kyu-Young; Jeong, Myung-Joon; Potthast, Antje; Liebner, Falk

    2017-10-01

    Cellulose is the renewable, biodegradable and abundant resource and is suggested as an alternative material to silica due to the high price and environmental load of silica. The first step for cellulose aerogel production is to dissolve cellulose, and hydrated calcium thiocyanate molten salt is one of the most effective solvents for preparing porous material. Cellulose aerogels were prepared from dissolved cellulose samples of different degree of polymerization (DP) and drying methods, and tested with shrinkage, density and mechanical strength. Supercritical CO2 dried cellulose aerogels shrank less compared to freeze-dried cellulose aerogels, whereas the densities were increased according to the DP increases in both cellulose aerogels. Furthermore, scanning electron microscope (SEM) images showed that the higher DP cellulose aerogels were more uniform with micro-porous structure. Regarding the mechanical strength of cellulose aerogels, supercritical CO2 dried cellulose aerogels with higher molecular weight were much more solid.

  15. Green composites of thermoplastic corn starch and recycled paper cellulose fibers

    Directory of Open Access Journals (Sweden)

    Amnuay Wattanakornsiri

    2011-08-01

    Full Text Available Ecological concerns have resulted in a renewed interest in environmental-friendly composites issues for sustainabledevelopment as a biodegradable renewable resource. In this work we used cellulose fibers from recycled newspaper as reinforcementfor thermoplastic starch in order to improve its mechanical, thermal and water resistance properties. The compositeswere prepared from corn starch plasticized by glycerol (30% wt/wt of glycerol to starch as matrix that was reinforcedwith micro-cellulose fibers, obtained from used newspaper, with fiber content ranging from 0 to 8% (wt/wt of fibers to matrix.Physical properties of composites were determined by mechanical tensile tests, differential scanning calorimetry, thermogravimetricanalysis, water absorption measurement and scanning electron microscopy. The results showed that higherfibers content raised the tensile strength and elastic modulus up to 175% and 292%, respectively, when compared to thenon-reinforced thermoplastic starch. The addition of the fibers improved the thermal resistance and decreased the waterabsorption up to 63%. Besides, scanning electron microscopy illustrated a good adhesion between matrix and fibers. Theseresults indicated that thermoplastic starch reinforced with recycled newspaper cellulose fibers could be fruitfully used ascommodity plastics being strong, cheap, abundant and recyclable.

  16. Graphene-cellulose paper flexible supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Zhe; Su, Yang; Li, Feng; Du, Jinhong; Cheng, Hui-Ming [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Da-Wei [ARC Centre of Excellence for Functional Nanomaterials, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Qld 4072 (Australia)

    2011-10-15

    A simple and scalable method to fabricate graphene-cellulose paper (GCP) membranes is reported; these membranes exhibit great advantages as freestanding and binder-free electrodes for flexible supercapacitors. The GCP electrode consists of a unique three-dimensional interwoven structure of graphene nanosheets and cellulose fibers and has excellent mechanical flexibility, good specific capacitance and power performance, and excellent cyclic stability. The electrical conductivity of the GCP membrane shows high stability with a decrease of only 6% after being bent 1000 times. This flexible GCP electrode has a high capacitance per geometric area of 81 mF cm{sup -2}, which is equivalent to a gravimetric capacitance of 120 F g{sup -1} of graphene, and retains >99% capacitance over 5000 cycles. Several types of flexible GCP-based polymer supercapacitors with various architectures are assembled to meet the power-energy requirements of typical flexible or printable electronics. Under highly flexible conditions, the supercapacitors show a high capacitance per geometric area of 46 mF cm{sup -2} for the complete devices. All the results demonstrate that polymer supercapacitors made using GCP membranes are versatile and may be used for flexible and portable micropower devices. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Anaerobic digestion of cellulosic wastes: laboratory tests

    International Nuclear Information System (INIS)

    Lee, D.D.; Donaldson, T.L.

    1984-11-01

    Anaerobic digestion is a potentially attractive technology for volume reduction of cellulosic wastes. A substantial fraction of the waste is converted to off-gas and a relatively small volume of biologically stabilized sludge is produced. Process development work is underway using a 75-L digester to verify rates and conversions obtained at the bench scale, to develop start-up and operating procedures, and to generate effluent for characterization and disposal studies. Three runs using batch and batch-fed conditions have been made lasting 36, 90, and over 200 days. Solids solubilization and gas production rates and total solids destruction have met or exceeded the target values of 0.6 g cellulose per L of reactor per day, 0.5 L off-gas per L of reactor per day, and 80% destruction of solids, respectively. Successful start-up procedures have been developed, and preliminary effluent characterization and disposal studies have been done. A simple dynamic process model has been constructed to aid in further process development and for use in process monitoring and control of a large-scale digester. 10 references, 17 figures, 4 tables

  18. Microbial reduction of uranium using cellulosic substrates

    International Nuclear Information System (INIS)

    Thombre, M.S.; Thomson, B.M.; Barton, L.L.

    1996-01-01

    Previous work at the University of New Mexico and elsewhere has shown that sulfate-reducing bacteria are capable of reducing uranium from the soluble +6 oxidation state to the insoluble +4 oxidation state. This chemistry forms the basis of a proposed ground water remediation strategy in which microbial reduction would be used to immobilize soluble uranium. One such system would consist of a subsurface permeable barrier which would stimulate microbial growth resulting in the reduction of sulfate and nitrate and immobilization of metals while permitting the unhindered flow of ground water through it. This research investigated some of the engineering considerations associated with a microbial reducing barrier such as identifying an appropriate biological substrate, estimating the rate of substrate utilization, and identifying the final fate of the contaminants concentrated in the barrier matrix. The performance of batch reactors and column systems that treated simulated plume water was evaluated using cellulose, wheat straw, alfalfa hay, sawdust, and soluble starch as substrates. The concentrations of sulfate, nitrate, and U(VI) were monitored over time. Precipitates from each system were collected, and the precipitated U(IV) was determined to be crystalline UO 2(s) by x-ray diffraction. The results of this study support the proposed use of cellulosic substrates as candidate barrier materials

  19. Radiation induced crosslinking of cellulose ethers

    International Nuclear Information System (INIS)

    Wach, A.R.; Mitomo, H.; Yoshii, F.; Kume, T.

    2002-01-01

    The effects of high-energy radiation on four ethers of cellulose: carboxymethyl (CMC); hydroxypropyl (HPC), hydroxyethyl (HEC) and methylcellulose (MC) were investigated. Polymers are irradiated in solid state and in aqueous solutions at various concentrations. Degree of substitution (DS) of the derivatives, the concentration of their aqueous solutions and irradiation conditions had a significant impact on the obtained products. Irradiation of polymers in solid state and in diluted aqueous solutions resulted in their degradation. However, it was found that for concentrated solutions gel formation occurred. Paste-like form of the initial material, when water plasticizes the bulk of polymer as well as the high dose rate, what prevents oxygen penetration of the polymer during irradiation, have been found favourable for hydrogel formation. Up to 95% of gel fraction was obtained from solutions of CMC with concentration over 50% irradiated by γ-rays or electron beam. It was pointed out that the ability to the formation of the three-dimensional network is related to the DS of anhydroglucose units and a type of chemical group introduced to main chain of cellulose. Produced hydrogels swelled markedly in water. Despite of the crosslinked structure they underwent degradation by the action of cellulase enzyme or microorganisms from compost, and can be included into the group of biodegradable materials. (author)

  20. Communication and Sensing Circuits on Cellulose

    Directory of Open Access Journals (Sweden)

    Federico Alimenti

    2015-06-01

    Full Text Available This paper proposes a review of several circuits for communication and wireless sensing applications implemented on cellulose-based materials. These circuits have been developed during the last years exploiting the adhesive copper laminate method. Such a technique relies on a copper adhesive tape that is shaped by a photo-lithographic process and then transferred to the hosting substrate (i.e., paper by means of a sacrificial layer. The presented circuits span from UHF oscillators to a mixer working at 24 GHz and constitute an almost complete set of building blocks that can be applied to a huge variety communication apparatuses. Each circuit is validated experimentally showing performance comparable with the state-of-the-art. This paper demonstrates that circuits on cellulose are capable of operating at record frequencies and that ultra- low cost, green i.e., recyclable and biodegradable materials can be a viable solution to realize high frequency hardware for the upcoming Internet of Things (IoT era.

  1. Catalytic modification of cellulose and hemicellulose - Sugarefine

    Energy Technology Data Exchange (ETDEWEB)

    Repo, T. [Helsinki Univ. (Finland),Laboratory of Inorganic Chemistry], email: timo.repo@helsinki.fi

    2012-07-01

    The main goal of the project is to develop catalytic methods for the modification of lignocellulose-based saccharides in the biorefineries. The products of these reactions could be used for example as biofuel components, raw materials for the chemical industry, solvents and precursors for biopolymers. The catalyst development aims at creating efficient, selective and green catalytic methods for profitable use in biorefineries. The project is divided in three work packages: In WP1 (Catalytic dehydration of cellulose) the aim is at developing non-toxic, efficient methods for the catalytic dehydration of cellulose the target molecule being here 5-hydroxymethylfurfural (5-HMF). 5-HMF is an interesting platform chemical for the production of fuel additives, solvents and polymers. In WP2 (Catalytic reduction), the objective of the catalytic reduction studies is to produce commercially interesting monofunctional chemicals, such as 1-butanol or 2-methyltetrahydrofuran (2-MeTHF). In WP3 (Catalytic oxidation), the research focuses on developing a green and efficient oxidation method for producing acids. Whereas acetic and formic acids are bulk chemicals, diacids such as glucaric and xylaric acids are valuable specialty chemicals for detergent, polymer and food production.

  2. Cellulose-hemicellulose interaction in wood secondary cell-wall

    International Nuclear Information System (INIS)

    Zhang, Ning; Li, Shi; Hong, Yu; Chen, Youping; Xiong, Liming

    2015-01-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose. (paper)

  3. Cellulose-hemicellulose interaction in wood secondary cell-wall

    Science.gov (United States)

    Zhang, Ning; Li, Shi; Xiong, Liming; Hong, Yu; Chen, Youping

    2015-12-01

    The wood cell wall features a tough and relatively rigid fiber reinforced composite structure. It acts as a pressure vessel, offering protection against mechanical stress. Cellulose microfibrils, hemicellulose and amorphous lignin are the three major components of wood. The structure of secondary cell wall could be imagined as the same as reinforced concrete, in which cellulose microfibrils acts as reinforcing steel bar and hemicellulose-lignin matrices act as the concrete. Therefore, the interface between cellulose and hemicellulose/lignin plays a significant role in determine the mechanical behavior of wood secondary cell wall. To this end, we present a molecular dynamics (MD) simulation study attempting to quantify the strength of the interface between cellulose microfibrils and hemicellulose. Since hemicellulose binds with adjacent cellulose microfibrils in various patterns, the atomistic models of hemicellulose-cellulose composites with three typical binding modes, i.e. bridge, loop and random binding modes are constructed. The effect of the shape of hemicellulose chain on the strength of hemicellulose-cellulose composites under shear loadings is investigated. The contact area as well as hydrogen bonds between cellulose and hemicellulose, together with the covalent bonds in backbone of hemicellulose chain are found to be the controlling parameters which determine the strength of the interfaces in the composite system. For the bridge binding model, the effect of shear loading direction on the strength of the cellulose material is also studied. The obtained results suggest that the shear strength of wood-inspired engineering composites can be optimized through maximizing the formations of the contributing hydrogen bonds between cellulose and hemicellulose.

  4. Production and characterization of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices

    Energy Technology Data Exchange (ETDEWEB)

    Zepon, Karine Modolon [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Petronilho, Fabricia [FICEXP, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil); Soldi, Valdir [POLIMAT, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Salmoria, Gean Vitor [CIMJECT, Departamento de Engenharia Mecânica, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Kanis, Luiz Alberto, E-mail: luiz.kanis@unisul.br [TECFARMA, Universidade do Sul de Santa Catarina, 88704-900 Tubarão, SC (Brazil)

    2014-11-01

    The production and evaluation of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices are reported herein. The matrices were melt extruded under nine different conditions, altering the temperature and the screw speed values. The surface morphology of the matrices was examined by scanning electron microscopy. The micrographs revealed the presence of non-melted silver sulfadiazine microparticles in the matrices extruded at lower temperature and screw speed values. The thermal properties were evaluated and the results for both the biopolymer and the drug indicated no thermal degradation during the melt extrusion process. The differential scanning analysis of the extrudate matrices showed a shift to lower temperatures for the silver sulfadiazine melting point compared with the non-extruded drug. The starch/cellulose acetate matrices containing silver sulfadiazine demonstrated significant inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus. In vivo inflammatory response tests showed that the extrudate matrices, with or without silver sulfadiazine, did not trigger chronic inflammatory processes. - Highlights: • Melt extruded bio-based matrices containing silver sulfadiazine was produced. • The silver sulfadiazine is stable during melt-extrusion. • The extrudate matrices shown bacterial growth inhibition. • The matrices obtained have potential to development wound healing membranes.

  5. Cellulosic ethanol. Potential, technology and development status

    Energy Technology Data Exchange (ETDEWEB)

    Rarbach, M. [Sued-Chemie AG, Muenchen (Germany)

    2012-07-01

    In times of rising oil prices and a growing energy demand, sustainable alternative energy sources are needed. Cellulosic ethanol is a sustainable biofuel, made from lignocellulosic feedstock such as agricultural residues (corn stover, cereal straw, bagasse) or dedicated energy crops. Its production is almost carbon neutral, doesn't compete with food or feed production and induces no land use changes. It constitutes a new energy source using an already existing renewable feedstock without needing any further production capacity and can thus play a major role on the way to more sustainability in transport and the chemical industry and reducing the dependence on the import of fossil resources. The potential for cellulosic ethanol is huge: In the US, the annual production of agricultural residues (cereal straw and corn stover) reached almost 384 million tons in 2009 and Brazil alone produced more than 670 million tons of sugar cane in 2009 yielding more than 100 million tons of bagasse (dry basis). And alone in the European Union, almost 300 million tons of crop straw are produced annually. The last years have seen success in the development and deployment in the field of cellulosic ethanol production. The main challenge thereby remains to demonstrate that the technology is economically feasible for the up-scaling to industrial scale. Clariant has developed the sunliquid {sup registered} process, a proprietary cellulosic ethanol technology that reaches highest greenhouse gas (GHG) emission savings while cutting production costs to a minimum. The sunliquid {sup registered} process for cellulosic ethanol matches the ambitious targets for economically and ecologically sustainable production and greenhouse gas reduction. It was developed using an integrated design concept. Highly optimized, feedstock and process specific biocatalysts and microorganisms ensure a highly efficient process with improved yields and feedstock-driven production costs. Integrated, on

  6. Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

    Science.gov (United States)

    Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

    2016-11-01

    Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

  7. Integrated production of nano-fibrillated cellulose and cellulosic biofuel (ethanol) by enzymatic fractionation of wood fibers

    Science.gov (United States)

    Junyong Zhu; Ronald Sabo; Xiaolin Luo

    2011-01-01

    This study demonstrates the feasibility of integrating the production of nano-fibrillated cellulose (NFC), a potentially highly valuable biomaterial, with sugar/biofuel (ethanol) from wood fibers. Commercial cellulase enzymes were used to fractionate the less recalcitrant amorphous cellulose from a bleached Kraft eucalyptus pulp, resulting in a highly crystalline and...

  8. Optimization of cellulose acrylate and grafted 4-vinylpyridine and 1-vinylimidazole synthesis

    Directory of Open Access Journals (Sweden)

    Bojanić Vaso

    2010-01-01

    Full Text Available Optimization of cellulose acrylate synthesis by reaction with sodium cellulosate and acryloyl chloride was carried out. Optimal conditions for conducting the synthesis reaction of cellulose acrylate were as follows: the molar ratio of cellulose/potassium-t-butoxide/acryloyl chloride was 1:3:10 and the optimal reaction time was 10 h. On the basis of elemental analysis with optimal conditions for conducting the reaction of cellulose acrylate, the percentage of substitution of glucose units in cellulose Y = 80.7%, and the degree of substitution of cellulose acrylate DS = 2.4 was determined. The grafting reaction of acrylate vinyl monomers onto cellulose in acetonitrile with initiator azoisobutyronitrile (AIBN in a nitrogen atmosphere was performed, by mixing for 5 h at acetonitrile boiling temperature. Radical copolymerization of synthesized cellulose acrylate and 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidinone and 9-vinylcarbazole, cellulose-poly-4-vinylpyridine (Cell-PVP, cellulose-poly-1- vinylimidazole (Cell-PVIm and cellulose-poly-1-vinyl-2-pyrrolidinone (Cell-P1V2P and cellulose-poly-9-vinylcarbazole (Cell-P9VK were synthesized. Acrylate cellulose and cellulose grafted copolymers were confirmed by IR spectroscopy, based on elementary analysis and the characteristics of grafted copolymers of cellulose were determined. The mass share of grafted copolymers, X, the relationship of derivative parts/cellulose vinyl group, Z, and the degree of grafting copolymers of cellulose (mass% were determined. In reaction of methyl iodide and cellulose-poly-4-vinylpyridine (Cell-PVP the cellulose-1-methyl-poly-4-vinylpyridine iodide (Cell-1-Me-PVPJ was synthesized. Cellulose acrylate and grafted copolymers were obtained with better thermal, electrochemical and ion-emulation properties for bonding of noble metals Au, Pt, Pd from water solutions. The synthesis optimization of cellulose acrylate was applied as a model for the synthesis of grafted

  9. Conductivity percolation in loosely compacted microcrystalline cellulose: An in situ study by dielectric spectroscopy during densification.

    Science.gov (United States)

    Nilsson, Martin; Frenning, Göran; Gråsjö, Johan; Alderborn, Göran; Strømme, Maria

    2006-10-19

    The present study aims at contributing to a complete understanding of the water-induced ionic charge transport in cellulose. The behavior of this transport in loosely compacted microcrystalline cellulose (MCC) powder was investigated as a function of density utilizing a new type of measurement setup, allowing for dielectric spectroscopy measurement in situ during compaction. The ionic conductivity in MCC was found to increase with increasing density until a leveling-out was observed for densities above approximately 0.7 g/cm3. Further, it was shown that the ionic conductivity vs density followed a percolation type behavior signifying the percolation of conductive paths in a 3D conducting network. The density percolation threshold was found to be between approximately 0.2 and 0.4 g/cm3, depending strongly on the cellulose moisture content. The observed percolation behavior was attributed to the forming of interparticulate bonds in the MCC and the percolation threshold dependence on moisture was linked to the moisture dependence of particle rearrangement and plastic deformation in MCC during compaction. The obtained results add to the understanding of the density-dependent water-induced ionic transport in cellulose showing that, at given moisture content, the two major parameters determining the magnitude of the conductivity are the connectedness of the interparticluate bonds and the connectedness of pores with a diameter in the 5-20 nm size range. At densities between approximately 0.7 and 1.2 g/cm3 both the bond and the pore networks have percolated, facilitating charge transport through the MCC compact.

  10. Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2015-01-01

    Full Text Available Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose.

  11. Corrosion inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, A O

    1965-12-29

    An acid corrosion-inhibiting composition consists essentially of a sugar, and an alkali metal salt selected from the group consisting of iodides and bromides. The weight ratio of the sugar to the alkali metal salt is between 2:1 and about 20,000:1. Also, a corrosion- inhibited phosphoric acid composition comprising at least about 20 wt% of phosphoric acid and between about 0.1 wt% and about 10 wt% of molasses, and between about 0.0005 wt% and about 1 wt% of potassium iodide. The weight ratio of molasses to iodide is greater than about 2:1. (11 claims)

  12. Inhibition of sulfate reduction in paddy soils

    Energy Technology Data Exchange (ETDEWEB)

    Vamos, R

    1958-12-13

    The hydrogen sulfide formed in waterlogged soils is a serious problem in rice cultivation. It inhibits the uptake of water and nutrients and may even cause root-rot. Results can best be obtained by preventing the formation of hydrogen sulfide. It is formed mainly by reduction of sulfate for which the cellulose-butyric acid fermentation provides the hydrogen source. Addition of ammonium or potassium nitrate prevents the formation of H/sub 2/S. The hydrogen produced by butyric acid fermentation is used to reduce nitrate and consequently cannot be utilized by the sulfate-reducing bacteria as a source of energy. 6 references.

  13. Packaging properties and control of Listeria monocytogenes in bologna by cellulosic films incorporated with pediocin

    Directory of Open Access Journals (Sweden)

    Paula Judith Pérez Espitia

    2013-09-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen, able to survive and proliferate at refrigeration temperatures. As a result, ready-to-eat meat products have been associated with major outbreaks. Producing meat products involves lethal preservation treatments, e.g. thermal treatments. Listeria contamination, however, may be introduced when products are sliced and packaged at retail businesses or delicatessens. In Brazil, sliced bologna is very popular at retail markets. After slicing, however, bologna has a short shelf-life. The aim of this work was to study the effects of pediocin incorporation on the load at break, water vapor permeability rate and structure, by microscopic analysis, of antimicrobial cellulosic packaging. The potential application of the developed packaging for the preservation of bologna and inhibition of Listeria biofilm formation was also studied. Cellulosic antimicrobial packaging films were produced with cellulose acetate and acetone. Pediocin (commercially available concentrate ALTA TM 2341 was incorporated at 30, 40 and 50 % w/w. The load at break of films was studied using the Universal Testing Machine (Instron at 10 °C and 25 °C. The water vapor permeability was determined by gravimetric method. A scanning electron microscope was used to study the developed packaging structure. Antimicrobial activity of films against Listeria innoucua and L. monocytogenes was tested both in vitro and in bologna samples. Results showed that values of load at break decreased with increasing concentrations of pediocin at 10 °C and 25 °C. Regarding water vapor permeability, only the control and 50 % pediocin films presented statistical difference, with the 50 % pediocin film being more permeable. In vitro tests showed antimicrobial activity against L. innocua. Cellulosic film with 50 % pediocin reduced L. monocytogenes growth on sliced bologna by 1.2 log cycles after 9 days and prevented biofilm formation on packaging and bologna

  14. beta. -1,4-glucan occurring in homogenate of Phaseolus aureus seedlings. Possible nascent stage of cellulose biosynthesis in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, S; Matsuda, K; Tamari, K

    1976-12-01

    A small amount of cytoplasmic ..beta..-1,4-glucan, which might be involved in the synthesis of cellulose in the cell wall, was found in the homogenate prepared from the hypocotyls of seedlings of Phaseolus aureus. Upon hydrolysis by cellulase of the 20,000xg pellet from the cytoplasmic fraction of segments incubated in a (/sup 14/C)-glucose solution, (/sup 14/C)-cellobiose was produced, with specific radioactivities 3 to 10 times greater than those of the cellobiose from cellulose in the cell wall at various incubation periods. The incoporation of radioactivity from (/sup 14/C)-glucose into this cytoplasmic ..beta..-1,4-glucan was therefore faster than that into cellulose constituting the cell wall. Hence, it seemed that the former ..beta..-1,4-glucan could be turned over. To examine whether the cytoplasmic ..beta..-1,4-glucan is carried by some subcellular components, cytoplasmic ..beta..-1,4-glucan in the cell was fractionated by differential centrifugation, two enzyme activities being measured as the markers of subcellular components. The distribution of ..beta..-1,4-glucan was similar to that of UDPG-glucosyl-transferase activity but not to that of IDP-ase activity. The result suggests that the cytoplasmic ..beta..-1,4-glucan has some relation to plasma membranes. Coumarin, known as a specific inhibitor for the biosynthesis of cellulose in plant cells, was shown to inhibit the incorporation of radio-carbon from (/sup 14/C)-glucose into cytoplasmic ..beta..-1,4-glucan to the same extent as that into cellulose in the cell wall of the hypocotyls.

  15. Optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production

    International Nuclear Information System (INIS)

    Bae, Hyeun Jong; Wi, Seung Gon; Lee, Yoon Gyo; Kim, Ho Myung; Kim, Su Bae

    2011-10-01

    The purpose of this project is optimization of upstream and development of cellulose hydrolysis process for cellulosic bio-ethanol production. The 2nd year Research scope includes: 1) Optimization of pre-treatment conditions for enzymatic hydrolysis of lignocellulosic biomass and 2) Demonstration of enzymatic hydrolysis by recombinant enzymes. To optimize the pretreatment, we applied two processes: a wet process (wet milling + popping), and dry process (popping + dry milling). Out of these, the wet process presented the best glucose yield with a 93.1% conversion, while the dry process yielded 69.6%, and the unpretreated process yielded <20%. The recombinant cellulolytic enzymes showed very high specific activity, about 80-1000 times on CMC and 13-70 times on filter paper at pH 3.5 and 55 .deg. C

  16. Adsorption of Saccharomyces cerevisiae onto cellulose and ecteola-cellulose films for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Lueng, K.L.; Joshi, S.; Yamazaki, H.

    1983-05-01

    Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Umodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 hours of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour. (Refs. 4).

  17. Advances in cellulosic conversion to fuels: engineering yeasts for cellulosic bioethanol and biodiesel production.

    Science.gov (United States)

    Ko, Ja Kyong; Lee, Sun-Mi

    2018-04-01

    Cellulosic fuels are expected to have great potential industrial applications in the near future, but they still face technical challenges to become cost-competitive fuels, thus presenting many opportunities for improvement. The economical production of viable biofuels requires metabolic engineering of microbial platforms to convert cellulosic biomass into biofuels with high titers and yields. Fortunately, integrating traditional and novel engineering strategies with advanced engineering toolboxes has allowed the development of more robust microbial platforms, thus expanding substrate ranges. This review highlights recent trends in the metabolic engineering of microbial platforms, such as the industrial yeasts Saccharomyces cerevisiae and Yarrowia lipolytica, for the production of renewable fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

    Gallagher, M. E.; Hockaday, W. C.; Snapp, S.; McSwiney, C.; Baldock, J.

    2010-12-01

    Corn grain biofuel crops produce the highest yields when the cropping ecosystem is not nitrogen (N)-limited, achieved by application of fertilizer. There are environmental consequences for excessive fertilizer application to crops, including greenhouse gas emissions, hypoxic “dead zones,” and health problems from N runoff into groundwater. The increase in corn acreage in response to demand for alternative fuels (i.e. ethanol) could exacerbate these problems, and divert food supplies to fuel production. A potential substitute for grain ethanol that could reduce some of these impacts is cellulosic ethanol. Cellulosic ethanol feedstocks include grasses (switchgrass), hardwoods, and crop residues (e.g. corn stover, wheat straw). It has been assumed that these feedstocks will require similar N fertilization rates to grain biofuel crops to maximize yields, but carbohydrate yield versus N application has not previously been monitored. We report the biochemical stocks (carbohydrate, protein, and lignin in Mg ha-1) of a corn ecosystem grown under varying N levels. We measured biochemical yield in Mg ha-1 within the grain, leaf and stem, and reproductive parts of corn plants grown at seven N fertilization rates (0-202 kg N ha-1), to evaluate the quantity and quality of these feedstocks across a N fertilization gradient. The N fertilization rate study was performed at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. Biochemical stocks were measured using 13C nuclear magnetic resonance spectroscopy (NMR), combined with a molecular mixing model (Baldock et al. 2004). Carbohydrate and lignin are the main biochemicals of interest in ethanol production since carbohydrate is the ethanol feedstock, and lignin hinders the carbohydrate to ethanol conversion process. We show that corn residue carbohydrate yields respond only weakly to N fertilization compared to grain. Grain carbohydrate yields plateau in response to fertilization at

  19. Bacterial Cellulose Ionogels as Chemosensory Supports.

    Science.gov (United States)

    Smith, Chip J; Wagle, Durgesh V; O'Neill, Hugh M; Evans, Barbara R; Baker, Sheila N; Baker, Gary A

    2017-11-01

    To fully leverage the advantages of ionic liquids for many applications, it is necessary to immobilize or encapsulate the fluids within an inert, robust, quasi-solid-state format that does not disrupt their many desirable, inherent features. The formation of ionogels represents a promising approach; however, many earlier approaches suffer from solvent/matrix incompatibility, optical opacity, embrittlement, matrix-limited thermal stability, and/or inadequate ionic liquid loading. We offer a solution to these limitations by demonstrating a straightforward and effective strategy toward flexible and durable ionogels comprising bacterial cellulose supports hosting in excess of 99% ionic liquid by total weight. Termed bacterial cellulose ionogels (BCIGs), these gels are prepared using a facile solvent-exchange process equally amenable to water-miscible and water-immiscible ionic liquids. A suite of characterization tools were used to study the preliminary (thermo)physical and structural properties of BCIGs, including no-deuterium nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction. Our analyses reveal that the weblike structure and high crystallinity of the host bacterial cellulose microfibrils are retained within the BCIG. Notably, not only can BCIGs be tailored in terms of shape, thickness, and choice of ionic liquid, they can also be designed to host virtually any desired active, functional species, including fluorescent probes, nanoparticles (e.g., quantum dots, carbon nanotubes), and gas-capture reagents. In this paper, we also present results for fluorescent designer BCIG chemosensor films responsive to ammonia or hydrogen sulfide vapors on the basis of incorporating selective fluorogenic probes within the ionogels. Additionally, a thermometric BCIG hosting the excimer-forming fluorophore 1,3-bis(1-pyrenyl)propane was devised which exhibited a ratiometric (two

  20. Dental glass ionomer cement reinforced by cellulose microfibers and cellulose nanocrystals

    International Nuclear Information System (INIS)

    Silva, Rafael M.; Pereira, Fabiano V.; Mota, Felipe A.P.; Watanabe, Evandro; Soares, Suelleng M.C.S.; Santos, Maria Helena

    2016-01-01

    The aim of this work was to evaluate if the addition of cellulose microfibers (CmF) or cellulose nanocrystals (CNC) would improve the mechanical properties of a commercial dental glass ionomer cement (GIC). Different amounts of CmF and CNC were previously prepared and then added to reinforce the GIC matrix while it was being manipulated. Test specimens with various concentrations of CmF or CNC in their total masses were fabricated and submitted to mechanical tests (to evaluate their compressive and diametral tensile strength, modulus, surface microhardness and wear resistance) and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The incorporation of CmF in the GIC matrix did not greatly improve the mechanical properties of GIC. However, the addition of a small amount of CNC in the GIC led to significant improvements in all of the mechanical properties evaluated: compressive strength (increased up to 110% compared with the control group), elastic modulus increased by 161%, diametral tensile strength increased by 53%, and the mass loss decreased from 10.95 to 3.87%. Because the composites presented a considerable increase in mechanical properties, the modification of the conventional GIC with CNC can represent a new and promising dental restorative material. - Highlights: • Cellulose microfibers (CmF) and cellulose nanocrystals (CNC) were prepared. • The CmF and CNC were incorporated in commercial dental glass ionomer cement (GIC). • Small amount of CNC improved significantly all the mechanical properties evaluated. • Modified GIC with CNC can represent a new and promising dental restorative material.

  1. Commercialization of cellulose nanofibril (CNF) and cellulose nanocrystal (CNC): pathway and challenges

    Science.gov (United States)

    Alan Rudie

    2017-01-01

    The status of pilot-scale production methods for cellulose nanorods or nanocrystals and the 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-0xyl (TEMPO) grade of cellu— lose nanofibrils are discussed. Both products appear to be poised for scale-up when markets develop, but there are a number of issues that need to be addressed. This chapter outlines concepts for conversion...

  2. Enhanced Cellulose Degradation Using Cellulase-Nanosphere Complexes

    Science.gov (United States)

    Blanchette, Craig; Lacayo, Catherine I.; Fischer, Nicholas O.; Hwang, Mona; Thelen, Michael P.

    2012-01-01

    Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production. PMID:22870287

  3. Obtaining of Peracetic Cellulose from Oat Straw for Paper Manufacturing

    Directory of Open Access Journals (Sweden)

    Tetyana V. Zelenchuk

    2017-10-01

    Full Text Available Background. Development of technology for obtaining peracetic pulp from oat straw and its use in the production of one of the paper mass types. Objective. Determination of peracetic cooking technological parameters’ optimal values for oat straw peracetic cellulose quality indicators. Methods. The oat straw cooking was carried out with peracetic acid at 95 ± 1 °C from 90 to 180 min for hydromodulus 8:1 and 7:1, using a sodium tungstate catalyst. To determine the oat straw peracetic cellulose mechanical indexes, laboratory samples of paper weighing 70 g/m2 were made. Results. Technological parameters’ optimum values (temperature, cooking duration, hydromodulus, hydrogen peroxide and acetic acid concentration for the oat straw delignification process were established. It is shown that the sodium tungstate catalyst addition to the cooking solution at a rate of up to 1 % of the plant raw material weight helps to reduce the lignin content in cellulose to 15 %. A diagram of the cellulose yield dependence on its residual lignin content for various methods of non-wood plant material species delignification is constructed. The high efficiency of the peracetic method for obtaining cellulose from non-wood plant raw materials, in particular from oat straw, has been confirmed. It is determined that the obtained peracetic cellulose from oat straw has high mechanical indexes. Conclusions. Oat straw peracetic cellulose can be used for the production of paper and cardboard mass types, in particular wrapping paper.

  4. Cellulosic Bionanocomposites: A Review of Preparation, Properties and Applications

    Directory of Open Access Journals (Sweden)

    Alain Dufresne

    2010-12-01

    Full Text Available Cellulose is the most abundant biomass material in nature. Extracted from natural fibers, its hierarchical and multi-level organization allows different kinds of nanoscaled cellulosic fillers—called cellulose nanocrystals or microfibrillated cellulose (MFC—to be obtained. Recently, such cellulose nanoparticles have been the focus of an exponentially increasing number of works or reviews devoted to understanding such materials and their applications. Major studies over the last decades have shown that cellulose nanoparticles could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging is being investigated, with continuous studies to find innovative solutions for efficient and sustainable systems. Processing is more and more important and different systems are detailed in this paper depending on the polymer solubility, i.e., (i hydrosoluble systems, (ii non-hydrosoluble systems, and (iii emulsion systems. This paper intends to give a clear overview of cellulose nanoparticles reinforced composites with more than 150 references by describing their preparation, characterization, properties and applications.

  5. Enhanced cellulose degradation using cellulase-nanosphere complexes.

    Science.gov (United States)

    Blanchette, Craig; Lacayo, Catherine I; Fischer, Nicholas O; Hwang, Mona; Thelen, Michael P

    2012-01-01

    Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

  6. Enhanced cellulose degradation using cellulase-nanosphere complexes.

    Directory of Open Access Journals (Sweden)

    Craig Blanchette

    Full Text Available Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC; however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

  7. Extraction and characterisation of cellulose nanocrystals from pineapple peel

    Directory of Open Access Journals (Sweden)

    Ana Raquel Madureira

    2018-04-01

    Full Text Available The potential of pineapple peel as a source of cellulose nanocrystals was evaluated. Peels skin from fresh-cut fruit was used as raw material. These residues were purified to remove pigments, lipids and hemicellulose, and a bleaching process for delignification was carried out for 4-6 h. All resulting products were characterised for their lignin, hemicellulose, cellulose and ash contents using standard techniques. Dry matter at the end was low (ca. 50% compared with the raw material (ca. 90%. The process applied resulted in ca. 20% (m/m of purified cellulose (ca. 80% purity, with ineligible levels of lignin and hemicellulose present, especially when using 6h of bleaching. The purified cellulose was subject to acid hydrolysis for nanocrystal extraction with two testing times, 30 and 60 minutes. These cellulose nanocrystals had small sizes (< 1000 nm, with high variability and negative zeta potential values. The time of extraction did not affect the nanocrystals’ chemical and physical properties. The use of 6 h of bleaching treatment during purification was shown to be more effective than 4 h. Pineapple peel was demonstrated to be a good source of cellulose for the production of cellulose nanocrystals.

  8. Electrocatalytic oxidation of cellulose at a gold electrode.

    Science.gov (United States)

    Sugano, Yasuhito; Latonen, Rose-Marie; Akieh-Pirkanniemi, Marceline; Bobacka, Johan; Ivaska, Ari

    2014-08-01

    The electrochemical properties of cellulose dissolved in NaOH solution at a Au surface were investigated by cyclic voltammetry, FTIR spectroscopy, the electrochemical quartz crystal microbalance technique, and electrochemical impedance spectroscopy. The reaction products were characterized by SEM, TEM, and FTIR and NMR spectroscopy. The results imply that cellulose is irreversibly oxidized. Adsorption and desorption of hydroxide ions at the Au surface during potential cycling have an important catalytic role in the reaction (e.g., approach of cellulose to the electrode surface, electron transfer, adsorption/desorption of the reaction species at the electrode surface). Moreover, two types of cellulose derivatives were obtained as products. One is a water-soluble cellulose derivative in which some hydroxyl groups are oxidized to carboxylic groups. The other derivative is a water-insoluble hybrid material composed of cellulose and Au nanoparticles (≈4 nm). Furthermore, a reaction scheme of the electrocatalytic oxidation of cellulose at a gold electrode in a basic medium is proposed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Cellulose supplementation early in life ameliorates colitis in adult mice.

    Directory of Open Access Journals (Sweden)

    Dorottya Nagy-Szakal

    Full Text Available Decreased consumption of dietary fibers, such as cellulose, has been proposed to promote the emergence of inflammatory bowel diseases (IBD: Crohn disease [CD] and ulcerative colitis [UC] where intestinal microbes are recognized to play an etiologic role. However, it is not known if transient fiber consumption during critical developmental periods may prevent consecutive intestinal inflammation. The incidence of IBD peaks in young adulthood indicating that pediatric environmental exposures may be important in the etiology of this disease group. We studied the effects of transient dietary cellulose supplementation on dextran sulfate sodium (DSS colitis susceptibility during the pediatric period in mice. Cellulose supplementation stimulated substantial shifts in the colonic mucosal microbiome. Several bacterial taxa decreased in relative abundance (e.g., Coriobacteriaceae [p = 0.001], and other taxa increased in abundance (e.g., Peptostreptococcaceae [p = 0.008] and Clostridiaceae [p = 0.048]. Some of these shifts persisted for 10 days following the cessation of cellulose supplementation. The changes in the gut microbiome were associated with transient trophic and anticolitic effects 10 days following the cessation of a cellulose-enriched diet, but these changes diminished by 40 days following reversal to a low cellulose diet. These findings emphasize the transient protective effect of dietary cellulose in the mammalian large bowel and highlight the potential role of dietary fibers in amelioration of intestinal inflammation.

  10. Mass spectrometric studies of fast pyrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Degenstein, John; Hurt, Matt; Murria, Priya; Easton, McKay; Choudhari, Harshavardhan; Yang, Linan; Riedeman, James; Carlsen, Mark; Nash, John; Agrawal, Rakesh; Delgass, W.; Ribeiro, Fabio; Kenttämaa, Hilkka

    2015-01-01

    A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose and also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.

  11. Chitosan Based Regenerated Cellulose Fibers Functionalized with Plasma and Ultrasound

    Directory of Open Access Journals (Sweden)

    Urška Vrabič Brodnjak

    2018-04-01

    Full Text Available The great potential of regenerated cellulose fibers, which offer excellent possibilities as a matrix for the design of bioactive materials, was the lead for our research. We focused on the surface modification of fibers to improve the sorption properties of regenerated cellulose and biocomposite regenerated cellulose/chitosan fibers, which are on the market. The purpose of our investigation was also the modification of regenerated cellulose fibers with the functionalization by chitosan as a means of obtaining similar properties to biocomposite regenerated cellulose/chitosan fibers on the market. Argon gas plasma was used for fiber surface activation and chitosan adsorption. Ultrasound was also used as a treatment procedure for the surface activation of regenerated cellulose fibers and treatment with chitosan. Analyses have shown that ultrasonic energy or plasma change the accessibility of free functional groups, structure and reactivity, especially in regenerated cellulose fibers. Changes that occurred in the morphology and in the structure of fibers were also reflected in their physical and chemical properties. Consequently, moisture content, sorption properties and water retention improved.

  12. Cellulose Supplementation Early in Life Ameliorates Colitis in Adult Mice

    Science.gov (United States)

    Nagy-Szakal, Dorottya; Hollister, Emily B.; Luna, Ruth Ann; Szigeti, Reka; Tatevian, Nina; Smith, C. Wayne; Versalovic, James; Kellermayer, Richard

    2013-01-01

    Decreased consumption of dietary fibers, such as cellulose, has been proposed to promote the emergence of inflammatory bowel diseases (IBD: Crohn disease [CD] and ulcerative colitis [UC]) where intestinal microbes are recognized to play an etiologic role. However, it is not known if transient fiber consumption during critical developmental periods may prevent consecutive intestinal inflammation. The incidence of IBD peaks in young adulthood indicating that pediatric environmental exposures may be important in the etiology of this disease group. We studied the effects of transient dietary cellulose supplementation on dextran sulfate sodium (DSS) colitis susceptibility during the pediatric period in mice. Cellulose supplementation stimulated substantial shifts in the colonic mucosal microbiome. Several bacterial taxa decreased in relative abundance (e.g., Coriobacteriaceae [p = 0.001]), and other taxa increased in abundance (e.g., Peptostreptococcaceae [p = 0.008] and Clostridiaceae [p = 0.048]). Some of these shifts persisted for 10 days following the cessation of cellulose supplementation. The changes in the gut microbiome were associated with transient trophic and anticolitic effects 10 days following the cessation of a cellulose-enriched diet, but these changes diminished by 40 days following reversal to a low cellulose diet. These findings emphasize the transient protective effect of dietary cellulose in the mammalian large bowel and highlight the potential role of dietary fibers in amelioration of intestinal inflammation. PMID:23437211

  13. Bacterial cellulose biosynthesis: diversity of operons, subunits, products and functions

    Science.gov (United States)

    Römling, Ute; Galperin, Michael Y.

    2015-01-01

    Summary Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits – which differ among various taxa – affect the enzymatic activity and product yield in vivo by modulating expression of biosynthesis apparatus, export of the nascent β-D-glucan polymer to the cell surface, and the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of the resulting biofilm, which is particularly important for interactions of bacteria with higher organisms that lead to rhizosphere colonization and modulate virulence of cellulose-producing bacterial pathogens inside and outside of host cells. Here we review the organization of four principal types of cellulose synthase operons found in various bacterial genomes, identify additional bcs genes that encode likely components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms formed by a variety of free-living and pathogenic bacteria and, for the latter, in the choice between acute infection and persistence in the host. PMID:26077867

  14. On the conflicting findings of Role of Cellulose-Crystallinity in Enzume Hydrolysis of Biomass

    Science.gov (United States)

    Umesh Agarwal; Sally Ralph

    2014-01-01

    In the field of conversion of biomass to ethanol, an important area of research is the enzymatic hydrolysis of cellulose. Once cellulose is converted to glucose, it can be easily fermented to ethanol. As the cellulosic ethanol technology stands now, costly pretreatments and high dosages of cellulases are needed to achieve complete hydrolysis of the cellulose fraction...

  15. Performance of cellulose derivatives in deep-fried battered snacks: Oil barrier and crispy properties

    NARCIS (Netherlands)

    Primo-Martín, C.; Sanz, T.; Steringa, D.W.; Salvador, A.; Fiszman, S.M.; Vliet, T. van

    2010-01-01

    The performance of batters containing cellulose derivatives (methyl cellulose (A4M), three hydroxypropylmethyl celluloses (E4M, F4M and K4M) with different degree of hydroxypropyl and/or methyl substitution and carboxymethyl cellulose (CMC)) to produce crispy deep-fried snacks crusts was studied by

  16. Morphological structure of Gluconacetobacter xylinus cellulose and cellulose-based organic-inorganic composite materials

    Science.gov (United States)

    Smyslov, R. Yu; Ezdakova, K. V.; Kopitsa, G. P.; Khripunov, A. K.; Bugrov, A. N.; Tkachenko, A. A.; Angelov, B.; Pipich, V.; Szekely, N. K.; Baranchikov, A. E.; Latysheva, E.; Chetverikov, Yu O.; Haramus, V.

    2017-05-01

    Scanning electron microscopy, ultra-small-angle neutron scattering (USANS), small-angle neutron and X-ray scattering (SANS and SAXS), as well as low-temperature nitrogen adsorption, were used in the studies of micro- and mesostructure of polymer matrix prepared from air-dry preliminarily disintegrated cellulose nano-gel film (synthesized by Gluconacetobacter xylinus) and the composites based on this bacterial cellulose. The composites included ZrO2 nanoparticles, Tb3+ in the form of low molecular weight salt and of metal-polymer complex with poly(vinylpyrrolydone)-poly(methacryloyl-o-aminobenzoic acid) copolymer. The combined analysis of the data obtained allowed revealing three levels of fractal organization in mesostructure of G. xylinus cellulose and its composites. It was shown that both the composition and an aggregation state of dopants have a significant impact on the structural characteristics of the organic-inorganic composites. The composites containing Tb3+ ions demonstrate efficient luminescence; its intensity is an order of magnitude higher in the case of the composites with the metal-polymer complex. It was found that there is the optimal content of ZrO2 nanoparticles in composites resulting in increased Tb3+ luminescence.

  17. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    Energy Technology Data Exchange (ETDEWEB)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J., E-mail: rosemarymj@lifecarehll.com

    2016-04-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  18. Biological evaluation of nanosilver incorporated cellulose pulp for hygiene products

    International Nuclear Information System (INIS)

    Kavitha Sankar, P.C.; Ramakrishnan, Reshmi; Rosemary, M.J.

    2016-01-01

    Cellulose pulp has a visible market share in personal hygiene products such as sanitary napkins and baby diapers. However it offers good surface for growth of microorganisms. Huge amount of research is going on in developing hygiene products that do not initiate microbial growth. The objective of the present work is to produce antibacterial cellulose pulp by depositing silver nanopowder on the cellulose fiber. The silver nanoparticles used were of less than 100 nm in size and were characterised using transmission electron microscopy and X-ray powder diffraction studies. Antibacterial activity of the functionalized cellulose pulp was proved by JIS L 1902 method. The in-vitro cytotoxicity, in-vivo vaginal irritation and intracutaneous reactivity studies were done with silver nanopowder incorporated cellulose pulp for introducing a new value added product to the market. Cytotoxicity evaluation suggested that the silver nanoparticle incorporated cellulose pulp is non-cytotoxic. No irritation and skin sensitization were identified in animals tested with specific extracts prepared from the test material in the in-vivo experiments. The results indicated that the silver nanopowder incorporated cellulose pulp meets the requirements of the standard practices recommended for evaluating the biological reactivity and has good biocompatibility, hence can be classified as a safe hygiene product. - Highlights: • Different amounts of silver nanoparticles (0.2 g–0.4 g/napkin) were added to cellulose pulp. • The silver nanoparticle incorporated cellulose pulp was proved to be antibacterial by JIS L 1902 method. • The minimum concentration of silver required for antibacterial activity with no cytotoxicity has been found out. • In-vivo vaginal irritation and intracutaneous reactivity studies confirmed the biocompatibility of the material.

  19. Plasma electrolytic liquefaction of cellulosic biomass

    Science.gov (United States)

    Dingliang, TANG; Xianhui, ZHANG; Si-ze, YANG

    2018-04-01

    In this paper, the rapid liquefaction of a corncob was achieved by plasma electrolysis, providing a new method for cellulosic biomass liquefaction. The liquefaction rate of the corncob was 95% after 5 min with polyethylene glycol and glycerol as the liquefying agent. The experiments not only showed that H+ ions catalyzed the liquefaction of the corncob, but also that using accelerated H+ ions, which were accelerated by an electric field, could effectively improve the liquefaction efficiency. There was an obvious discharge phenomenon, in which the generated radicals efficiently heated the solution and liquefied the biomass, in the process of plasma electrolytic liquefaction. Finally, the optimum parameters of the corncob liquefaction were obtained by experimentation, and the liquefaction products were analyzed.

  20. Availability of crop cellulosics for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, R.D.

    1982-10-01

    Past estimates of cellulosic resources available from Canadian agriculture totalled over 23 million tonnes of cereal grain straw and corn stover residues surplus to soil and animal requirements. A new much reduced estimate, based on four detailed regional studies that also include previously unassessed resources such as chaff, oilseed hulls, and food processing wastes, is suggested. Eleven million tonnes are currently available from all residue sources for energy conversion by different processes. Only five million tonnes are identified as potentially usable in ethanol production plants were they to be constructed. Additional resource opportunities may become available in future from currently underutilized land, especially saline soils, novel processing techniques of conventional grains and forages, innovative cropping systems that may increase the yield of agricultural biomass, and new food/feed/fuel (i.e. multi-purpose) crops such as kochia, milkweed, and Jerusalem artichoke. 27 refs., 1 fig., 1 tab.