Non-cellulosic Compounds Research Articles

Cortical microtubule rearrangements and cell wall patterning.

Plant cortical microtubules, which form a highly ordered array beneath the plasma membrane, play essential roles in determining cell shape and function by directing the arrangement of cellulosic and non-cellulosic compounds on the cell surface. Interphase transverse arrays of cortical microtubules self-organize through their dynamic instability and inter-microtubule interactions, and by branch-form microtubule nucleation and severing. Recent studies revealed that distinct spatial signals including ROP GTPase, cellular geometry, and mechanical stress regulate the behavior of cortical microtubules at the subcellular and supercellular levels, giving rise to dramatic rearrangements in the cortical microtubule array in response to internal and external cues. Increasing evidence indicates that negative regulators of microtubules also contribute to the rearrangement of the cortical microtubule array. In this review, I summarize recent insights into how the rearrangement of the cortical microtubule array leads to proper, flexible cell wall patterning.

Simultaneous Saccharification and Fermentation of Dilute Acid Pretreated Red Algae (Gelidiella acerosa) for Bioethanol Production

Studies on the production of bioethanol from red algae (Gelidiella acerosa) by dilute acid pretreatment and simultaneous saccharification and fermentation were performed. The non-cellulosic compounds were significantly reduced during dilute acid pretreatment. Results obtained in simultaneous saccharification and fermentation showed that the ethanol yield was affected by the changes in pretreatment, liquid to solid ratio, enzyme concentration, and pH. Kinetic study was also performed with experimental value to analyze the production rate and their actual means of production process. The maximum 91.62% of theoretical yield of ethanol was obtained at 36 h of simultaneous saccharification and fermentation under optimized conditions.

Microfibrillated cellulose and cellulose nanopaper from Miscanthus biogas production residue

The feasibility of the isolation of microfibrillated cellulose (MFC) from the fibrous residue of the production of biogas from Miscanthus straw was investigated. Studying two variants of continuous anaerobic fermentation carried out at mesophilic and thermophilic conditions, respectively, MFC was obtained after extensive extraction of non-cellulosic compounds and mechanical fibrillation. MFC crystallinity and molar mass were drastically decreased in biogas residue with increasing temperature in processing. Nonetheless, nanopaper produced from all variants showed acceptable mechanical performance considering its significantly degraded structure. High failure strain at low density is of particular interest for the thermophilic variant. Infrared spectroscopy indicates changes in surface chemistry of the thermophilic variant, which may explain its peculiar tensile properties. Production of fibrillated cellulose from biogas residue is suggested as highly interesting route for the generation of additional value from bioenergy processes.

Synergetic effect of DC air plasma and cellulase enzyme treatment on the hydrophilicity of cotton fabric

The effects of DC air plasma and cellulase enzyme treatments on the hydrophilicity of cotton fabric samples were investigated. Cotton fabric samples were treated with DC air plasma (P), cellulase enzyme (E), enzyme treatment preceded by plasma (PE) and plasma treatment preceded by enzyme (EP) to improve the hydrophilicity. The physico-chemical changes that occurred during the treatments were studied using dynamic wicking test, SEM, XRD, UATR-FTIR, weight loss and air permeability measurements. The UATR-FTIR results revealed that, for EP treated fabrics, there is a decrease in the intensity of C 1–O–C 4 peak (894 cm −1) indicating the glycosidic bond breakage with an increase in the intensity of C O peak (1734 cm −1) due to oxidation at C 6, C 1/C 4 carbon by enzyme and plasma treatments. SEM and XRD results reveal that, plasma and enzyme treatment leads to surface etching, removing the non-cellulosic compounds thereby increasing the hydrophilicity of the cotton fabrics. The synergetic effect of plasma and enzyme treatments on physical and chemical properties of the cotton fabric is studied and the results are discussed.

Characterization of Hemp Fiber Using Microwave-Assisted Extraction (MAE) Pretreatment

The main objective of this paper was to investigate a low cost pretreatment method, namely microwave-assisted extraction(MAE) pretreatment, which could be applied to hemp degumming with low environmental impact. Degumming index, contrast of different pretreatment methods, transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and single fiber tensile testing were used to characterise the effect of pretreatment on hemp fibers. In this paper, the results of degumming effect were given comparing MAE pretreatment with acid pretreatment for hemp degumming. It was found that the MAE pretreatment could remove non-cellulosic compounds from hemp bundles effectively with very short period of time. Meanwhile, seen from SEM micrographs, the fibers pretreated by MAE were cleaner than that of fibers pretreated by acid. These results suggested that MAE pretreatment was higher efficiency and more environmental friendly than traditional pretreatment methods.

Hemp fibre reinforced composites using chelator and enzyme treatments

The main objective of the current work was to investigate using chelator treatment, and combined chelator and enzyme treatments, to separate hemp fibre from its bundles, as well as remove non-cellulosic compounds, and thus therefore improve the interfacial bonding in the composite. Wet chemical analysis, FTIR, X-ray diffraction (XRD), thermal analysis and single fibre tensile testing were used to characterise the effect of treatment on hemp fibres. The higher chelator concentration treated hemp fibre composites had the highest tensile strength of 42 MPa, an increase of 19% compared to composites with untreated hemp fibre.

Evaluating cell wall structure and composition of developing cotton fibers using Fourier transform infrared spectroscopy and thermogravimetric analysis

AbstractUniversal attenuated total reflectance Fourier transform infrared (UATR‐FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to investigate the structural changes of cotton (Gossypium hirsutum L.) fibers as a function of developmental programming. The presence of noncellulosic compounds (wax, protein, hemicelluloses, pectic substances, amino acids, etc.) was evident from FTIR spectra of fibers at 10, 14, 17, and 20 dpa (day postanthesis). The vibration corresponding to the noncellulosic compounds disappeared at 36 dpa. Furthermore, independent TGA analysis supported the results obtained with FTIR, showing that the transition from primary cell wall synthesis to secondary cell wall synthesis occurs at or around 20 dpa. This study is the first to report on the use of the UATR‐FTIR and TGA to elucidate structural changes during cotton fiber development. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Pre-treatment of Flax Fibers for use in Rotationally Molded Biocomposites

The objective of this study was to determine the effects of pre-treated flax fibers on the performance of the fiber-reinforced composites. Lack of good interfacial adhesion and poor resistance to moisture absorption make the use of natural fiber-reinforced composites less attractive. In order to improve fiber/matrix interfacial properties, fibers were subjected to chemical treatments, namely, mercerization, silane treatment, benzoylation, and peroxide treatment. Selective removal of non-cellulosic compounds constitutes the main objective of the chemical treatments of flax fibers to improve the performance of fiber-reinforced composites. Flax fibers were derived from Saskatchewan-grown flax straws. Composites consisting of high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE) or HDPE/LLDPE mix, chemically treated fibers and additives were prepared by the extrusion process. The test samples were prepared by rotational molding. The fiber surface morphology and the tensile fracture surfaces of the composites were characterized by scanning electron microscopy (SEM). The effects of the different chemical treatments on the mechanical and the physical properties of natural fiber-reinforced composites were investigated. The differential scanning calorimetry (DSC) was used to measure the melting point of the fiber-reinforced composites.

Analysis of the oxidation of cellulose fibres by titration and XPS

The purpose of this study was to evaluate the effect of selective oxidation on the surface properties of cotton cellulose fibres. Four different methods to evaluate the accessibility, nature and content of ionisable acidic groups (charge) in the fibres were applied: potentiometric and conductometric titrations, polyelectrolyte adsorption and X-ray photoelectron spectroscopy (XPS). The results from this combination of methods show that two processes take place when the oxidation method is applied: elimination of low molecular mass non-cellulosic compounds and formation of new acidic groups in the cellulose chains. Which of these processes is predominating depends on oxidation time, but the first one is initially more important. Polyelectrolyte adsorption and XPS show that the surface concentration of acidic groups is considerably lower than the bulk concentration, i.e. during oxidation the content of carboxyl groups in the surface region decreases, while it increases in amorphous regions. The decrease is due to the dissolution of low molecular weight compounds; the increase is due to the formation of new acidic groups. The use of titration methods in combination with XPS appears to be a very useful tool for identification of the formation and distribution of ionic groups in cotton fibres and their surfaces.

Discovery of Pectin-degrading Enzymes and Directed Evolution of a Novel Pectate Lyase for Processing Cotton Fabric

There is a growing need in the textile industry for more economical and environmentally responsible approaches to improve the scouring process as part of the pretreatment of cotton fabric. Enzymatic methods using pectin-degrading enzymes are potentially valuable candidates in this effort because they could reduce the amount of toxic alkaline chemicals currently used. Using high throughput screening of complex environmental DNA libraries more than 40 novel microbial pectate lyases were discovered, and their enzymatic properties were characterized. Several candidate enzymes were found that possessed pH optima and specific activities on pectic material in cotton fibers compatible with their use in the scouring process. However, none exhibited the desired temperature characteristics. Therefore, a candidate enzyme was selected for evolution. Using Gene Site Saturation Mutagenesistrade mark technology, 36 single site mutants exhibiting improved thermotolerance were produced. A combinatorial library derived from the 12 best performing single site mutants was then generated by using Gene Reassemblytrade mark technology. Nineteen variants with further improved thermotolerance were produced. These variants were tested for both improved thermotolerance and performance in the bioscouring application. The best performing variant (CO14) contained eight mutations and had a melting temperature 16 degrees C higher than the wild type enzyme while retaining the same specific activity at 50 degrees C. Optimal temperature of the evolved enzyme was 70 degrees C, which is 20 degrees C higher than the wild type. Scouring results obtained with the evolved enzyme were significantly better than the results obtained with chemical scouring, making it possible to replace the conventional and environmentally harmful chemical scouring process.

Characterizing the Noncellulosics in Developing Cotton Fibers

Surface wetting measurements and several analytical techniques including FTIR/ATR, DSC, TGA, and pyrolysis-GC/MS are used to characterize the noncellulosic components of developing cotton fibers as intact components of the fiber structure. Water contact angle measurements are most sensitive to the presence of hydrophobic compounds on the surfaces of cotton fibers of all ages and to their removal by alkaline scouring. In general, FTIR/ATR, DSC, TGA, and pyrolysis-GC/MS provide clear evidence of specific noncellulosic components in developing cotton fibers through the onset of secondary celt wall synthesis. Waxy compounds are evident by their melting endotherms in DSC thermograms, carbonyl bands in FTIR spectra, and mass spectra in the untreated developing fibers between 12 and 17 dpa. Pectins are detected by. FTIR in the 14 dpa and mature fibers. FTIR/ATR measure ments indicate the presence of proteins in untreated fibers up to 16 dpa and water-rinsed fibers up to 18 dpa. The presence of proteins in 14 dpa fibers is also detected by pyrolysis-GC/MS data. Among the analytical techniques, only pyrolysis-GC/MS can detect the presence of noncellulosic compounds in 27 dpa fibers. Detection of noncellulosics by the other techniques diminishes as the proportion of cellulose rapidly increases with the onset of secondary cell wall synthesis.

US 4,923,909 Method of adding additives to polymers

Pineapple crown is an important source of cellulose that is still going to waste because of the lack of knowledge about their economic uses. The isolation of cellulose nanocrystals (CNC) from pineapple crown leaf (PCL) wastes arises as an important alternative to use PCL wastes in high value-added applications, and has not been reported yet. In this study, CNC were successfully extracted from PCL wastes using chemical treatments followed by acid hydrolysis using sulfuric acid. FTIR results confirmed the removal of the non-cellulosic compounds of PCL through the mercerization and bleaching treatments. SEM and AFM showed that the diameter of PCL fibers was reduced from 18 μm to 39 nm after the hydrolysis reaction, resulting in CNC with rod-like shape. The obtained CNC showed cellulose I crystalline structure with high crystallinity index (73%). The thermal degradation of CNC started at 124 °C, what was attributed to the presence of surface sulfate groups identified by elemental analysis. The high hydrophilicity of CNC was verified by its high moisture content and absorption. The results showed that the CNC isolated from PCL have interesting properties to be used in many liquid media applications, besides their use as reinforcement in nanocomposites.

Culm Strength of Barley

Grass culms are known to differ in breaking strength, but there is little physicochemical data to explain the response. The fourth internode of four brittle and two nonbrittle barley (Hordeum vulgare L.) strains were used for physical and chemical studies of culm strength. Inner and outer culm diameters of brittle strains (3.6 +/- 0.2 and 5.0 +/- 0.1 millimeters) were not significantly different from those of nonbrittle strains (3.9 +/- 0.2 and 5.2 +/- 0.2 millimeters). Maximum bending stress, at which the culm was broken, was 192 +/- 34 g/mm(2) for brittle and 490 +/- 38 g/mm(2) for nonbrittle strains. Wall thickness and cell dimensions of epidermal, sclerenchyma, and parenchyma cells were measured in culm cross sections. The area of cell wall per unit cell area for each tissue was significantly correlated with the maximum bending stress (r = 0.93 for epidermis, 0.90 for sclerenchyma, and 0.84 for parenchyma). Cell walls of brittle culms had 6 to 64% as much cellulose content as those of nonbrittle culms. Maximum bending stress correlated significantly with cellulose content of the cell walls (r = 0.93), but not with the contents of noncellulosic compounds. The lower cellulose content of the brittle culm was significantly correlated with brittleness.

Chemical Profiling of Washed and Mechanically Cleaned Cotton

Cotton samples were analyzed after water washing or mechanical cleaning to com pare the effects of such processes on chemical content of the bulk cotton. Water extracts of the samples were analyzed for organic carbon content by measuring total organic carbon and for ionizable species by measuring conductance. Total solids content and pH of the extracts were also determined before and after washing or cleaning. The level of noncellulosic organic compounds in the bulk samples was evaluated by extraction of the cotton samples with 2-amiftoethanot. The effect of washing and cleaning on volatiles evolved from the bulk samples was compared by gas chromatography/mass spectrometry measurements. All analyses of water extracts showed only slight changes after mechanical cleaning on a Shirley Analyzer, while large decreases in all values were found after water washing. Analyses of water extracts of cottons washed in the laboratory gave results close to those obtained on a "medical grade" cotton.

A method for cellulose determination

The usual metods for cellulose determinations, excepting those in which the material is decomposed by total hydrolysis, are principally methods for producing cellulose preparations. In these the non-cellulosic compounds are tried to be removed as thoroughly as possible without decomposing the cellulose. However, the preparations obtained still contain different non-cellulosic components for which corrections must be made. In the method proposed by the authors a crude cellulose preparation is produced by a relatively mild treatment, and corrections are made for crude lignin and pentosans. The main feature in producing the crude cellulose preparation is shaking the samples with 3N NaOH solution in pressure bottles in a boiling water bath. The method appears to give readable results for fodder materials. For woods the results are evidently too high, especially due to mannan in the crude cellulose.