Studies on the Carbohydrates of Horse Radish,Cochlearis Armoracia L

In the root of horse radish, sucrose, fructose, glucose and two unknown fructose-oligosac-charides were found in the form of free sugars, in the decreasing order just given, and large amounts of starch, hot 50% methanol-soluble polysaccharide, water-soluble polysaccharide, pectin, hemicellulose, cellulose and a small amount of lignin were found as polysaccharides. As the constructive sugar of these polysaccharides, the following, i.e., glucose, fructose, galactose, arabinose, galacturonic acid and xylose were detected.     

Optimization of processing conditions for the fractionation of triticale straw using pressurized low polarity water

Pressurized low polarity water (PLPW) fractionation of triticale straw was optimized to maximize hemicellulose and lignin yield, and to produce a cellulose rich fraction for biofuels production. The optimum PLPW conditions for hemicellulose yield was determined to be 165 °C, with a flow rate of 115 mL/min, and a solvent-to-solid ratio of 60 mL/g. Hemicellulose and lignin yield generally increased with increasing temperature and solvent-to-solid ratio. There was a small decrease in hemicellulose yield with an increase in flow rate. Minimum lignin content of the triticale straw residue after extraction was predicted to occur at a processing condition of 206 °C, 160 mL/min, and 67 mL/g. PLPW was successful in removing 73-78% of the hemicellulose, leaving a cellulose rich fraction (65% glucose concentration). Lignin was equally distributed between the solid residues and the extracts and most of the hemicellulose was extracted in oligomer form. Remaining solid residues after fractionation were highly digestible by cellulase enzymes.     

Succession and activity of microorganisms in stored bagasse

Summary Fresh sugarcane bagasse was fermented under defined conditions and investigated regarding a microbial succession during fermentation, in view of the enzyme activities of microorganisms against the main bagasse components: sucrose, pectin, hemicellulose, cellulose, and lignin.Altogether, 400 pure cultures of microorganisms were obtained from 8 g bagasse during 6.5 days of storage. This flora consists of bacteria (74%), actinomycetes (6%), yeasts (13%), and fungi (7%). The yeasts dominate in early fermentation, followed by bacteria, and then by actinomycetes and fungi.This succession coincides with the enzymic activities of the isolated organisms during fermentation. At first, residual sugar is consumed predominantly by the yeasts. Then the bacteria degrade the pectin, the hemicellulose, and in parts, the cellulose. Later, the actinomycetes and the fungi imperfecti attack the hemicellulose, the cellulose, and, partly, the lignin within the bagasse fiber.These results are corroborated by investigations using bagasse from bulk storage.     

Cell wall biochemistry and biomechanics of harvested white asparagus shoots as affected by temperature

The effects of temperature on the dynamics of changes in shoot mechanical properties, cell wall components, relevant soluble sugars and respiration activity of harvested white asparagus spears were investigated during a 7-day storage period. All functional cell wall components of asparagus spears increased closely temperature dependent. The content of soluble glucose declined with a similar temporal dynamics and to a comparable degree, indicating a major carbon flow of this storage sugar into cell walls (60–70%). Irrespective of temperature, the contents of stored soluble fructose and sucrose remained more or less constant. Lower temperatures reduced cell wall development but do not significantly affect the relative carbon flow from storage sugars into cell walls or maintenance respiration. Compared with cell walls, maintenance respiration is by far the smaller carbon sink in stored asparagus spears. Temperature differentially affects the absolute amount and the relative contribution of the different cell wall components and the temporal dynamics of changes in structural carbohydrate and lignin content. At higher temperatures, secondary cell wall thickening resulted mainly from a large increase in cellulose content. The pronounced increase in the fractions of cellulose and especially lignin may stress the important role of lignin in cell wall strengthening. While the fraction of cell wall proteins decreased, those of hemicellulose and the pectic components were not influenced.     

iTRAQ-based quantitative secretome analysis of Phanerochaete chrysosporium

The basidiomycete fungi such as Phanerochaete chrysosporium secrete large amount of hydrolytic and oxidative enzymes and degrade lignocellulosic biomass. The lignin depolymerizing proteins were extensively studied, but cellulose, hemicellulose and pectin hydrolyzing enzymes were poorly explored. In this study P. chrysosporium was grown in cellulose, lignin and mixture of cellulose and lignin, and secretory proteins were quantified by isobaric tag for relative and absolute quantitation (iTRAQ)-based quantitative proteomics using liquid chromatography tandem mass spectrometry (LC-MS/MS). An iTRAQ quantified 117 enzymes comprising cellulose hydrolyzing endoglucanases, exoglucanases, beta-glucosidases; hemicelluloses hydrolyzing xylanases, acetylxylan esterases, mannosidases, mannanases; pectin-degrading enzymes polygalacturonase, rhamnogalacturonase, arabinose and lignin degrading protein belonging to oxidoreductase family. Under cellulose and cellulose with lignin culture conditions, enzymes such as endoglucanases, exoglucanases, β-glucosidases and cellobiose dehydrogenase were significantly upregulated and iTRAQ data suggested hydrolytic and oxidative cellulose degradation. When lignin was used as a major carbon source, enzymes such as copper radical oxidase, isoamyl oxidase, glutathione S-transferase, thioredoxin peroxidase, quinone oxidoreductase, aryl alcohol oxidase, pyranose 2-oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase were expressed and significantly regulated. This study explored cellulose, hemicellulose, pectin and lignin degrading enzymes of P. chrysosporium that are valuable for lignocellulosic bioenergy.     

Changes in cell-wall polysaccharides from the mesocarp of grape berries during veraison

Softening of grape berries ( Vitis vinifera L. × V. labruscana cv. Kyoho) was evaluated by studying changes in composition and degradation of cell-wall polysaccharides. The grape berry softens at the beginning of the second growth cycle many weeks before harvest. The softening stage is called 'veraison' by viticulturists. On day 50 after full bloom, green hard berries (before veraison [BV]), softening berries (veraison [V]) and partly peel colored berries (C) were selected from the same clusters. In addition, mature berries (M) were collected on day 78 after full bloom. Mesocarp tissues at each stage were fractionated into hot water-soluble (WS), hot EDTA-soluble (pectin), alkali-soluble (hemicellulose) and residual (cellulose) fractions. Neutral and acidic sugar contents of WS and pectin fractions decreased only after the V stage, while the neutral sugar content of the hemicellulose fraction decreased from the BV to V stages. Cellulose content constantly decreased as the berry ripened, but the large decrease was found from the BV to V stages. Molecular masses of pectic and hemicellulosic polysaccharides decreased from the BV to V stages. Hemicellulosic xyloglucan was markedly depolymerized from the BV to V stages. The neutral and acidic sugar composition of each fraction changed little during the berry ripening. These data indicated that softening of berry during veraison involved the depolymerization of pectin and xyloglucan molecules and decrease in the amounts of hemicellulose and cellulose.     

Hydrothermal treatment of wheat straw at pilot plant scale using a three-step reactor system aiming at high hemicellulose recovery, high cellulose digestibility and low lignin hydrolysis

A pilot plant (IBUS) consisting of three reactors was used for hydrothermal treatment of wheat straw (120-150 kg/h) aiming at co-production of bioethanol (from sugars) and electricity (from lignin). The first reactor step was pre-soaking at 80 degrees C, the second extraction of hemicellulose at 170-180 degrees C and the third improvement of the enzymatic cellulose convertibility at 195 degrees C. Water added to the third reactor passed countercurrent to straw. The highest water addition (600 kg/h) gave the highest hemicellulose recovery (83%). With no water addition xylose degradation occurred resulting in low hemicellulose recovery (33%) but also in high glucose yield in the enzymatic hydrolysis (72 g/100g glucose in straw). Under these conditions most of the lignin was retained in the fibre fraction, which resulted in a lignin rich residue with high combustion energy (up to 31 MJ/kg) after enzymatic hydrolysis of cellulose and hemicellulose.     

High Rate Production in Static Culture of Bacterial Cellulose from Sucrose by a Newly Isolated Acetobacter Strain

For the industrial production of bacterial cellulose from sucrose in static cultures, the possibility of a high rate of cellulose production was investigated. An Acetobacter strain, S-35, which had been isolated from a grape, was selected from 1500 isolates. This strain was found to produce a large amount of cellulose from either glucose or fructose. Using this strain, high cellulose production rates of 3.3g/liter/d or 40g/m²/d from sucrose were seen in static culture.     

Cell wall changes in white spruce (Picea glauca) needles subjected to repeated drought stress

White spruce [ Picea glauca (Moench) Voss] seedlings were preconditioned by subjecting them to 3 cycles of a mild drought stress. After 1 week of stress relief their water status, soluble carbohydrate content and cell wall composition in newly formed needles were examined and compared with those in control seedlings. Both preconditioned and control seedlings were subsequently subjected to a severe drought stress and again analyzed. Preconditioning treatment both before and during subsequent stress exposure lowered osmotic potentials at full hydration, and after the loss of turgor, decreased lignin content and increased hemicellulose content of the cell walls. Severe drought had similar but more drastic effects on seedling water relations, sugar accumulation and cell wall hemicellulose content; it also decreased cell wall pectin levels. The decrease in pectin levels was accompanied by a loss of galactose and glucose from pectic substances. Little change in cellulose content was observed as a result of preconditioning and severe drought.     

Sugarcane Internode Composition During Crop Development

Sugarcane sugar and bagasse can be utilized for the production of ethanol or other biofuels. A better understanding of the changes in composition with development along the stalk and with crop development will maximize the usage of sugarcane for this purpose. Two experiments were designed to elucidate internode composition changes during the growing season. In experiment 1, an internode of stalks of 5 modern cultivars were marked at the start of elongation, and then sampled every 1 to 2?weeks from July until October. Sugars were extracted and assayed, and a sequential detergent method was used to estimate hemicellulose, cellulose, and lignin contents. In experiment 2, internodes 1, 3, 5, 7, 9, and 11 down the stalk were sampled in late July (grand growth) and late September (ripening). Internode length, fresh weight, dry weight, water content, and sugar contents were determined as well as cell wall composition. Both experiments were repeated in 2?years. As internodes elongated, total sugar increased, and hemicellulose decreased as a proportion of neutral detergent fiber, while cellulose and lignin increased. After elongation, sucrose and lignin increased, and cellulose content decreased with internode age. The variability in cell wall composition among the five cultivars suggests that selection for desirable composition may be possible. In Experiment 2, hemicellulose contents were lower, and lignin and ash contents were higher at ripening than during grand growth. Delaying sugarcane harvest to maximize sucrose content may decrease bagasse suitability for cellulosic ethanol production because of the increased lignin content.     

Symplastic and apoplastic sugar contents in gall tissues and callus of the sumac (Rhus chinensis MILL.)

To elucidate the role of cell wall in interaction with gall-inducing organisms, symplastic and apoplastic sugar contents in different shapes of gall tissue of the sumac (Rhus chinensis Mill.) were compared with those of the callus. The gall tissues with vascular cylinders, intercellular spaces and callus were fractionated into symplastic [methanol (MeOH), hot water (HW), and starch] fractions and apoplastic [pectin, hemicellulose, trifluoroacetic acid (TFA)-soluble, and cellulose] fractions. Symplastic sugar content of gall tissues was higher than that of callus. In apoplastic (cell wall) fractions, the cellulose content of gall tissues was lower than that of callus, due to large amount of pectin with high ratio of uronic acid (UA) and hemicellulose with low ratio of UA. Analysis of neutral sugar component of the hemicellulosic, TFA-soluble fraction showed that arabinose (side chain) and galactose (backbone) of arabinogalactan were rich in gall tissues and callus. The gall tissues had higher glucose and lower xylose contents than the callus. These results suggest that the structure of cell wall polysaccharides of gall changed during its development with an increase in symplastic sugar contents. The feeding activities occuring in gall by the gall-inducers were discussed.     

Influence of steam pretreatment severity on post‐treatments used to enhance the enzymatic hydrolysis of pretreated softwoods at low enzyme loadings

It is recognized that some form of post‐treatment will usually be required if reasonable hydrolysis yields (>60%) of steam pretreated softwood are to be achieved when using low enzyme loadings (5 FPU/g cellulose). In the work reported here we modified/removed lignin from steam pretreated softwood while investigating the influence that the severity of pretreatment might have on the effectiveness of subsequent post‐treatments. Although treatment at a lower severity could provide better overall hemicellulose recovery, post‐treatment was not as effective on the cellulosic component. Pretreatment at medium severity resulted in the best compromise, providing reasonable recovery of the water soluble hemicellulose sugars and the use of post‐treatment conditions that significantly increased the enzymatic hydrolysis of the water insoluble cellulosic component. Post‐treatment with alkaline hydrogen peroxide or neutral sulfonation resulted in 62% cellulose hydrolysis at an enzyme loading of 5 FPU/g cellulose, which was four times greater than was obtained when the cellulosic fraction was not post‐treated. When the enzyme loading was increased to 15 FPU/g cellulose, the post‐treated cellulosic fraction was almost completely hydrolyzed to glucose. Despite the higher lignin content (44%) of the sulfonated substrate, similar hydrolysis yields to those achieved after alkaline peroxide post‐treatment (14% lignin content) indicated that, in addition to lignin removal, lignin modification also plays an important role in influencing the effectiveness of hydrolysis when low enzyme loadings are used. Biotechnol. Bioeng. 2011;108: 2300–2311. © 2011 Wiley Periodicals, Inc.     

Genotypic variations in non-structural carbohydrate and cell-wall components of the stem in rice, sorghum, and sugar vane

We evaluated genetic variations in the non-structural carbohydrate (NSC) and the cell-wall components of stem in rice, sorghum, and sugar cane to assess the potential suitability of these gramineous crops for bioethanol production. For NSC, the maximum soluble sugar concentration was highest in sugar cane, followed by sorghum with sucrose. The major NSC in rice was starch, but there were wide variations in the starch to soluble sugar ratios among the cultivars. The total concentration of cell-wall components was negatively correlated with the NSC concentration, indicating competition for carbon sources. Among the cell-wall components, lignin was relatively stable within each group. The major sugar species composing hemicellulose was xylose in all crop groups, but there were differences in composition, with a higher fraction of arabinose and glucose in rice as compared to the other crops. In rice, there was less lignin than in sorghum or sugar cane; this might be advantageous for the efficient saccharification of cellulose.     

Hexose kinases of avocado

The subcellular location and properties of enzymes concerned with the phosphorylation of glucose and fructose in avocado (Persea americana Mill. cv. Hass) have been studied. A substantial amount of glucose-phosphorylating activity was particulate and fractionation of extracts by sucrose density gradient centrifugation indicated that most of this activity was associated with the mitochondria. Three hexose-phosphorylating enzymes were resolved by DEAE-cellulose chromatography of the cytosolic fraction. These were a hexokinase (EC 2.7.1.1), which had strong preference for glucose as substrate, and two specific fructokinases (EC 2.7.1.4). ATP was the preferred phosphoryl donor for the hexose kinases of avocado.     

Solid state fermentation of oat straw by Polyporus sp A-336 and the effect of added sugars

Summary Supplementing oat straw in SSF by Polyporus sp A-336 with xylose, mannose, glucose and arabinogalactan at levels of 5 and 10% of straw weight stimulated lignin degradation and cellulose hydrolysis. Degradation of lignin, hemicellulose and cellulose was monitored for 30 days in plain straw, and straw plus xylose and showed that xylose shortened the lag in lignin breakdown and slowed hemicellulose utilization. At 24 days, similar polymer losses occurred in both systems and enzymatic cellulose hydrolysis had reached a maximum of 47% weight loss.     

Genotypic Variations in Non-Structural Carbohydrate and Cell-Wall Components of the Stem in Rice,Sorghum, and Sugar Vane

We evaluated genetic variations in the non-structural carbohydrate (NSC) and the cell-wall components of stem in rice, sorghum, and sugar cane to assess the potential suitability of these gramineous crops for bioethanol production. For NSC, the maximum soluble sugar concentration was highest in sugar cane, followed by sorghum with sucrose. The major NSC in rice was starch, but there were wide variations in the starch to soluble sugar ratios among the cultivars. The total concentration of cell-wall components was negatively correlated with the NSC concentration, indicating competition for carbon sources. Among the cell-wall components, lignin was relatively stable within each group. The major sugar species composing hemicellulose was xylose in all crop groups, but there were differences in composition, with a higher fraction of arabinose and glucose in rice as compared to the other crops. In rice, there was less lignin than in sorghum or sugar cane; this might be advantageous for the efficient saccharification of cellulose.     

Hydrothermal treatment and ethanol pulping of sunflower stalks

The influence of temperature in the hydrothermal treatment of sunflower stalks on the composition of the liquid fraction obtained was examined. The remaining solid fraction was subjected to ethanol pulping in order to obtain pulp that was used to produce paper sheets. The pulp was characterized in terms of yield, kappa index, viscosity, and cellulose, hemicellulose and lignin contents; and the paper sheets in terms of breaking length, stretch, burst index and tear index. Hydrothermal treatment of the raw material at 190 degrees C provided a liquid phase with maximal hemicellulose-derived oligomers and monosaccharide (glucose, xylose and arabinose) contents (26.9 and 4.2 g/L, respectively). Pulping the solid fraction obtained by hydrothermal treatment at 180 degrees C, with 70% ethanol at a liquid/solid ratio of 8:1 at 170 degrees C for 120 min provided pulp with properties on a par with those of soda pulp from the sunflower stalks, namely: 36.3% yield, 69.1% cellulose, 12.6% hemicellulose, 18.2% lignin and 551 ml/g viscosity. Also, paper sheets obtained from the ethanol pulp were similar in breaking length (3.8 km), stretch (1.23%), burst index (1.15 kN/g) and tear index (2.04 m Nm(2)/g) to those provided by soda pulp.     

Pectin from transgenic flax shives regulates extracellular matrix remodelling in human skin fibroblasts

Pectin, a polysaccharide polymer from the plant cell wall, is an underestimated natural resource with many potential applications in the food and medical industries. Here we present, for the first time, the chemical composition of pectin obtained from flax shives, a by-product of flax fibre processing. The shives from transgenic flax overexpressing β-glucanase were analysed, revealing that genetic modification caused an increase in content of lignin, hemicellulose and pectin, without changes to cellulose, rearrangement of the structure of pectin and cellulose, a decrease in the content of phenolic compounds associated with the cell wall, and an increase in antioxidant capacity of the pectin CDTA fraction. The influence of pectin extract on the extracellular matrix remodelling process was verified. In fibroblast skin cells with induced oxidative stress, addition of pectin caused a reversal of the decrease of mRNA collagen genes, an increase of matrix metalloproteinase, interleukin 6 and MCP-1 gene expression, and a reduction in levels of TIMP-1 and SOCS-1 mRNA. The obtained results, in particular strong antioxidant properties of flax shives pectin from the CDTA-soluble fraction and its significant influence on genes participating in extracellular matrix remodelling, suggest the possible application of flax shives pectin in the wound healing process.     

Dietary fibre components and pectin chemical features of peels during ripening in banana and plantain varieties

The effects of the ripeness stage of banana (Musa AAA) and plantain (Musa AAB) peels on neutral detergent fibre, acid detergent fibre, cellulose, hemicelluloses, lignin, pectin contents, and pectin chemical features were studied. Plantain peels contained a higher amount of lignin but had a lower hemicellulose content than banana peels. A sequential extraction of pectins showed that acid extraction was the most efficient to isolate banana peel pectins, whereas an ammonium oxalate extraction was more appropriate for plantain peels. In all the stages of maturation, the pectin content in banana peels was higher compared to plantain peels. Moreover, the galacturonic acid and methoxy group contents in banana peels were higher than in plantain peels. The average molecular weights of the extracted pectins were in the range of 132.6-573.8 kDa and were not dependant on peel variety, while the stage of maturation did not affect the dietary fibre yields and the composition in pectic polysaccharides in a consistent manner. This study has showed that banana peels are a potential source of dietary fibres and pectins.