Characterization Of Hemicelluloses Research Articles

Extraction and characterization of hemicellulose and lignin contents of areca fiber

Extraction and characterization of hemicellulose and lignin contents of areca fiber

Characterization of hemicellulose in Cunninghamia lanceolata stem during xylogenesis

In this study, hemicellulose was isolated from the apical, middle and basal segments of C. lanceolata stem to investigate the dynamic change of its structure during xylogenesis. Results showed that the C. lanceolata hemicellulose is mainly consisted of O-acetylgalactoglucomannan (GGM) which backbone is alternately linked by β-d-mannopyranosyl (Manp) and β-d-glucopyranosyl (Glcp) via (1 → 4)-glycosidic bond, while the side chains are α-d-galactopyranosyl (Galp) and acetyl. In addition, 4-O-methylglucuronoarabinoxylan (GAX) is another dominant structure of C. lanceolata hemicellulose which contains a linear backbone of (1 → 4)-β-d-xylopyranosyl (Xylp) and side chains of 4-O-Me-α-d-glucuronic acid (MeGlcpA) and α-L-arabinofuranose (Araf). The thickness of the cell wall, the ratio of GGM/GAX and the molecular weight of hemicellulose were increased as the extension of growth time. The degree of glycosyl substitutions of xylan and mannan was decreased from 10.34 % (apical) to 8.38 % (basal) and from 15.63 % (apical) to 10.49 % (basal), respectively. However, the total degree of acetylation was enhanced from 0.28 (apical) to 0.37 (basal). Transcriptome analysis showed that genes (CSLA9, IRX9H1, IRX10L, IRX15L, GMGT1, TBL19, TBL25, GUX2, GUX3, GXM1, F8H1 and F8H2) related to hemicellulose biosynthesis are mainly expressed in mature part. This study is of great significance for genetic breeding and high-value utilization of C. lanceolata.

Isolation and characterisation of hemicelluloses from oil palm empty fruit bunches

Isolation and characterisation of hemicelluloses from oil palm empty fruit bunches

Characterization of hemicellulose during xylogenesis in rare tree species Castanopsis hystrix

Hemicellulose is an important component of the plant cell wall which vary in structure and composition between plant species. The research of hemicellulose structures is primarily focused on fast-growing plants during xylogenesis, with slow-growing and rare trees receiving the least attention. Here, hemicellulose structure of the rare species Castanopsis hystrix during xylogenesis was analyzed. Acetyl methyl glucuronide xylan was the most common type of hemicellulose in C. hystrix, with a unique tetrasaccharide structure at the reducing end. Hemicellulose type, structure, molecular weight, thermal stability, biosynthesis and acetyl substitution content and pattern remained stable during the xylogenesis in C. hystrix, which could be attributed to its slow growth. The stable polymer type, low side chain modification and high acetyl substitution of hemicellulose throughout the stems are among the reasons for the hardness and corrosion resistance properties of C. hystrix wood. Genetic modification can be used to improve these properties.

Extraction and Characterization of Hemicelluloses from a Softwood Acid Sulfite Pulp.

Hemicelluloses were extracted from a softwood acid sulfite pulp in a three-step procedure. Further delignification step resulted in a holocellulose pulp containing only 1.7 wt.% of the lignin left. Cold caustic extraction (CCE) with 18 wt.% NaOH at 60 °C for 1 h was performed to solubilize hemicelluloses of the holocellulose. An unbleached cellulose pulp was then obtained 97% pure, which indicates that 89% of the hemicelluloses were removed. After purification, extraction yields between 1.1 wt.% and 9.5 wt.% were obtained from the delignified pulp and the hemicelluloses’ chemical compositions and structures were investigated by 1H, 13C nuclear magnetic resonance spectroscopy (NMR) and two-dimensional NMR by correlation spectroscopy (2D-COSY) and proton-detected heteronuclear single-quantum correlation (2D-HSQC), high-performance anion-exchange chromatography coupled with a pulsed amperometry detector (HPAEC-PAD), size-exclusion chromatography coupled with a refractive index detector (SEC-RI) and thermogravimetric analyses (TGA). Hemicelluloses were obtained with a purity of 96%, with short cellulosic chains as the only residue. Sulfite pulping modified the hemicelluloses’ structure, and it was found that two types of hemicelluloses were isolated, glucomannans, predominant at 67%, and methylglucuronoxylans. Finally, alkali-soluble hemicelluloses displayed relatively narrow size distributions and low molar masses, Mw varying between 18,900 and 30,000 g/mol after acid sulfite pulping.

Characterization of hemicellulose in Cassava (Manihot esculenta Crantz) stem during xylogenesis

Cassava is one of the three major potato crops due to the high starch content in its tubers. Unlike most current studies on the utilization of cassava tubers, our research is mainly focused on the stem of cassava plant. Through nuclear magnetic resonance (NMR), fourier transform infrared spectrometer (FTIR) and other methods, we found that cassava stalk hemicellulose consists of β-1,4 glycosidic bond-linked xylan backbone with a tetrasaccharide reducing end and decorated with methylated glucuronic acid, acetyl groups and a high degree of arabinose substitutions. Hemicellulose content gradually increased from the upper to the lower parts of the stem. The apical part of cassava stalk contained more branched and heterogeneous glycans than the middle and basal parts, and the molecular weight of hemicellulose increased from top to bottom. Our findings will be helpful in understanding of structural variations of cassava hemicellulose during xylogenesis, as well as in better utilization of cassava plant waste in industry.

Characterization of hemicelluloses in sugarcane (Saccharum spp. hybrids) culm during xylogenesis

Hemicelluloses are effective renewable biopolymers that can be used in many different industrial processes and preparations. In plants, the content of hemicellulose might change with different developmental stages and/or tissues. Thus, in here chemical and structural differences in hemicellulose isolated from the apical, middle and basal segments of sugarcane stem were characterized using chemical techniques. Further, difference in expression levels of genes related to synthesis of hemicelluloses from these three segments were studied by RNA-seq and qRT-PCR etc. The sugarcane hemicellulose backbone was xylose residues connected via β-1,4 glycosidic linkages which was further substituted with arabinose, acetyl and glucuronic acid side chains. Hemicellulose content was higher in the middle and basal segments with less backbone substitutions compared to apical segments. In terms of gene expression, hemicellulose synthesis and modification genes were intensely expressed in middle and basal segments. Taken together, our research describes differences in hemicellulose content and substitutions in sugarcane during xylogenesis, which will increase our knowledge for finding more refined use of sugarcane bagasse.

Extraction and Characterization of Hemicellulose from Eucalyptus By-product: Assessment of Enzymatic Hydrolysis to Produce Xylooligosaccharides.

Eucalyptus wood is the primary source of fibers to produce paper and cellulose in South American countries. The major by-product generated in the cellulose industry is sawdust derived from chip wood production, which is designated as Eucalyptus by-product (EB). The xylooligosaccharides (XOS) are xylose-based oligomers with proven effects over maintenance and stimulation of beneficial human gut bacteria. This study reported the EB extraction and characterization along with an assessment of hemicellulose hydrolysis using commercial xylanases to produce XOS. Hemicellulose derived from extracted and NaClO2 pretreated (HEEBPT) presented xylan content of 55%, which was similar to 58.5% found in commercial Birchwood hemicellulose (CBH). The enzymatic hydrolysis of HEEBPT and CBH presented 30% as maximum conversion of xylan into XOS without significant difference among the enzymatic extracts evaluated. The XOS production from EB was proven as a technically feasible alternative to recover a value-added product from hemicellulosic fraction generated in the cellulose industry. However, lignin removal with NaClO2 from EB affects the feasibility of an industrial process because they generate toxic compounds in the pretreatment step. Thus, further studies with alternative reagents, such as ionic liquids, are required to asses selectively lignin removal from EB. Graphical Abstract.

Characterization of hemicelluloses from leaves and tops of the CC 8475, CC 8592, and V 7151 varieties of sugarcane (Saccharum officinarum L

In this research, the types of hemicellulose that predominate in the leaves and tops of the three most cultivated varieties (CC 8475, CC 8592, V 7151) of sugarcane (Saccharum officinarum L.) in Valle del Cauca, Colombia were determined. Hemicellulose analyses were performed after delignification with sodium chlorite and extraction with 18% NaOH and 24% KOH containing 0.26 M NaBH4. The main components of hemicellulose were identified via FTIR and NMR spectroscopy, and monomeric sugars were identified via HPLC. Hemicellulose A composed of arabinoxylans, glucomannans and arabinogalactactans and hemicellulose B primarily composed of arabinoxylans were extracted. The hemicelluloses of the Colombian varieties were more stable against heat than those of the Venezuelan variety. The results of this project allowed discovery of the potential use of agricultural sugarcane residues for bioethanol production because they have a holocellulose content of more than 60%.

Characterization of hemicelluloses in Phyllostachys edulis (moso bamboo) culm during xylogenesis

Hemicelluloses are β-(1→4)-linked backbone polysaccharides found in plant cell walls that include xyloglucans, xylans, mannans and glucomannans, and play important roles in plant tissue configuration. In this study, hemicelluloses were isolated from the apical, middle and basal segments of 6 m Phyllostachys edulis culm using KOH and DMSO extraction procedures, respectively. Chemical composition and structural characterization of hemicellulosic fractions were comparatively investigated by a combination of HPLC, GPC, FT-IR, 1H-, 13C-, HSQC NMR and TGA techniques. Our results show that the main chain of hemicellulose in P. edulis consists of glucuronoarabinoxylans (GAXs) with backbone 1, 4-β-d-Xyl, and side chain arabinose, glucuronic acid and acetylation. Hemicellulose content and molecular weight increased with culm xylogenesis in P. edulis. Our results provide new insights on the dynamics of hemicellulose structure in culm xylogenesis in P. edulis.

Characterization of hemicelluloses in process streams in thermomechanical and chemi-thermomechanical pulp mills

Increased interest in hemicelluloses as a renewable source of biopolymers has resulted in an interest in hemicelluloses in process streams in pulp mills. The aim of this study was to compare potential positions for the withdrawal of hemicelluloses from mechanical pulp mills. Samples were withdrawn at a total of fourteen positions from two thermomechanical and two chemi-thermomechanical pulp mills. The molecular mass distributions of hemicelluloses and lignin were determined by size-exclusion chromatography. Hemicelluloses showed peaks in the molecular mass interval of 0.2–2 kDa and 4–60 kDa, whereas lignin showed peaks in the range of 0.5–4 kDa, but no peak in the high-molecular-mass region. Glucomannan accounts for approximately two-thirds of the hemicellulose content of softwood, and mannan and glucan were thus the dominating saccharides in all samples. Mannan was preferentially found in fractions with a molecular mass ranging from 4 to 22 kDa.

Characterization of hemicelluloses from Neolamarckia cadamba (Rubiaceae) during xylogenesis

In this study, hemicelluloses were isolated from the apical, middle and basal segments of N. cadamba using a 2N KOH extraction procedure. Chemical composition and structural characterization of the three hemicellulosic fractions obtained were comparatively investigated by a combination of HPLC, GPC, FTIR, 1H,13C, HSQC NMR and TGA techniques. According to the sugar analysis and spectral results, (4-O-methyl) glucuronoxylan was the primary hemicellulose identified in the samples with trace levels of mannan also present. All of the three samples showed spherical polymers in 0.005M sodium phosphate solution (containing 0.02N NaCl). Xylan in the middle and basal segment stems had higher molecular weights. Our findings show that during xylogenesis in N. cadamba, changes are observed in xylan content and molecular weight.

Extraction, Addition and Characterization of Hemicelluloses from Corn Cobs to Development of Paper Properties

The corncob is a product found in significant amounts in the residues of agriculture, which has potential for use underexplored. This paper presents a study of the chemical characterization of corn cobs, extraction and application of hemicelluloses present in these wastes. Two fractions of hemicelluloses were obtained, the first being obtained after neutralization and precipitation of the alkaline solution and the second after addition of ethanol in the supernatant of the same solution. Handsheets were made by using bleached kraft eucalyptus pulp, and adding hemicelluloses. After that, their physical and mechanical properties were evaluated, according to TAPPI Standard. An increase in the resistance was observed to drainage and in the properties directly affected by the inter-fiber bonds with the content increase of hemicelluloses and also obtaining handsheets with lower bulk with content increase of these carbohydrates.

Production, Purification and Characterization of Hemicellulose from Penicillium janthinellum 3CHP

Penicillium janthinellum 3CHP, a mesophilic fungal strain, isolated from the pine forest of Simla hill was found to produce an array of hemicelluloses when grown in urea medium with sorghum straw as the carbon source. For purification these enzymes, were subjected to ion exchange chromatography. The active fractions pertaining to á-arabinofuranosidase obtained from it were pooled and concentrated using PM-10 (10 KDa cut off) fitted into an Amicon cell and further purified by gel filtration chromatography. Active fractions which exhibited high á-arabinofuranosidase activity in gel filtration chromatography were again pooled, concentrated and analyzed by SDS PAGE and zymogram development using L-umbelliferyl arabinofuranoside as substrate. Two isoforms of á-arabinofuranosidase were observed with molecular weight of approximately 60 and 80 KDa respectively. á-arabinofuranosidase, was further characterized with respect to various parameters such as temperature, pH, effect of various metal ions and chemicals, substrate specificity, and thermo-stability DOI: http://dx.doi.org/10.3126/njst.v14i2.10425 Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 123-130

Fractionation and characterization of hemicelluloses from young bamboo (Phyllostachys pubescens Mazel) leaves

Bamboo leaves are considered as an important source of bioactive molecules. In this work, leaves from young bamboo (Phyllostachys pubescens Mazel) aged 3 months were subjected to aqueous extraction and 2% NaOH solution extraction followed by precipitation in ethanol–water medium with different ethanol concentrations. The dissolved hemicellulosic polysaccharides presented a total recovery of 67.83% based on the total hemicellulose content in bamboo leaves. Chemical analysis of the fractions was performed by sugar composition analysis, Fourier-transform infrared spectrometry, and 1D nuclear magnetic resonance imaging. The results revealed that all polysaccharide fractions contained xylose, arabinose, glucose, galactose, ribose, and uronic acid. The polysaccharides from young bamboo leaves mainly consisted of arabinoxylans, arabinogalactans, and non-cellulosic β-d-glucans having (1→3)- and (1→4)-glucosidic linkages. The content of these polysaccharides was found to vary among the fractions depending on the separation method. Finally, the thermal behavior was also discussed.

Binding Ability of Corn Cobs Hemicellulose toward Cadmium

Non-Starch Polysaccahride (NSP) is an agricultural byproduct containing of cellulose, hemicelluloses, and lignin. Hemicellulose has a hydroxyl functional group and carboxylic function on the monomer hemicellulose used as a binding ability for cadmium ion and hence as a pharmaceutical active ingredient to prevent cadmium toxicity. The purpose of this study is to isolate and evaluate hemicelluloses from corn cobs as a binding ability toward cadmium ion. The study is conducted by isolating the corn cobs in such way using 0.2 M NaOH, characterization of hemicellulose from corn cobs produced by Infra Red Spectrofotometry. Binding ability of corn cobs hemicellulose (CCH) was done in 3 ways. The first, it was by titrimetric with cadmium 3 mg/cm3 as a titrant and indicator of 0.05 N NaOH. The second, it was by in vitro test at pH 2 as a comparison to use pectin. The third, the in vivo test was conducted in 3 variations of treatment covering CCH 10 mg, 100 mcg of cadmium for 10 weeks. Assay of cadmium was conducted using atomic absorption spectrophotometry with flame at a wavelength of 228.8 nm. The research result showed that the highest yield of hemicellulose (12.04%) was obtained from delignication with 0.03 M NaOH in 60% ethanol and 3% H2O2, hemicellulose isolation with 500 cm3 of 0.2 M NaOH, and precipitation with 1:4 ratio of 10% acetic acid in 95% ethanol. Characteristics of CCH on infrared vibration methods provide vibrational hemicellulose in the region of 1820-1600 cm-1. It meant that the functional group carbonyl was present, and the vibration widened near 3400-2400 cm-1. It indicated that there was the functional group vibration region of hydroxyl. It also meant that there was carboxylic group and finger print at 1500-500 cm-1. Test results of the titrimetric holding ability showed that CCH was binding 100 mg of cadmium (46.17 ± 0.9256) mg or 46.17%. Binding ability test results at pH 2 showed that 300 mg of CCH yield was binding 30 mg cadmium of (26.68 ± 0.1490) mg or 88.93%. The results of in vivo tests showed that cadmium levels decreased by 95.05%. Based on the exposure, it can be concluded that the CCH isolation yields of 12.04% and can reduce cadmium levels in the blood. It means that the CCH can be used as a chelating agent of cadmium ions by in vitro and in vivo.

Physicochemical Characterization of Hemicelluloses Obtained by Graded Ethanol Precipitation from Sweet Sorghum Stem

Physicochemical Characterization of Hemicelluloses Obtained by Graded Ethanol Precipitation from Sweet Sorghum Stem

Isolation and Characterization of Hemicelluloses from Cottonseed Coat Waste

Isolation and Characterization of Hemicelluloses from Cottonseed Coat Waste

Extraction and characterisation of hemicelluloses from maize stem

Extraction and characterisation of hemicelluloses are very important for converting them into functional materials and chemicals. To develop a method for isolation of hemicelluloses from all cell walls. Sequential steps using 90% dioxane, 80% acidic dioxane, 100% dimethyl sulphoxide and 8% NaOH were used for extraction of the hemicellulosic preparations (H(1), H(2), H(3) and H(4)) from maize stem. Advanced NMR techniques were used for the analysis of native hemicelluloses. Hemicelluloses with high yieldd were isolated from all cell walls, and contained arabinoxylan as the major polysaccharide. H(3) was substituted by α-L-arabinofuranose, α-D-xylopyranose, and acetyl groups (degree of saturation = 0.12/0.09) at O-3/O-2 of xylan. H(4) had a long continuous side chain of arabinose residues, and associated closely with non-cellulosic glucose. The hemicelluloses formed more linkages with guaiacyl lignins, and some p-coumaric acids built a bridge between hemicelluloses and lignin in maize stem. This modified method is successful for the isolation of hemicelluloses with high yields from all cell walls of maize stem.

Extraction and characterization of hemicelluloses from flax shives by different methods

Hemicelluloses were extracted from flax shives using pressurized low-polarity water (PLPW), pressurized aqueous ethanol (PAE), microwave-assisted water (MW-Water) or aqueous ethanol (MW-EtOH), and precipitated with ethanol. Hemicelluloses still remaining in solution were further separated using ultrafiltration. All samples were characterized with chemical analysis, ion-moderated partition chromatography (IMP), size exclusion chromatography (SEC), and Fourier transform infrared (FT-IR) spectroscopy. PLPW, PAE, MW-Water and MW-EtOH extracted 90, 80, 18, and 40% of the total hemicelluloses, respectively. The molecular weight of the ethanol-precipitated hemicelluloses ranged from approximately 11,000 to 40,000 Da and the ethanol-soluble low-molecular weight hemicelluloses were about 1700 Da. High-molecular weight hemicellulose isolated from PAE extracts contained ∼23% lignin, while that from the PLPW extracts contained ∼5% lignin. Low-molecular weight hemicelluloses separated by ultrafiltration from PLPW and PAE extracts contained similar amounts of lignin (∼20%). However, the yield of low-molecular weight hemicelluloses from PLPW was higher (∼15%) compared to that from PAE (∼6%). The FT-IR results revealed the specific band maximum at 1220 cm −1 and the bands between 1175 and 1000 cm −1 which are typical of xylans.