Enzymes for Hemicellulose Degradation

2022 ◽  
pp. 199-220
Author(s):  
Wichanee Bankeeree ◽  
Sehanat Prasongsuk ◽  
Pongtharin Lotrakul ◽  
Suraini Abd‐Aziz ◽  
Hunsa Punnapayak
Keyword(s):  
Hemicellulose Degradation

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

Sorption and thermodynamic properties of juvenile Pinus sylvestris L. wood after 103 years of submersion

Holzforschung ◽  
2008 ◽  
Vol 62 (6) ◽  
Author(s):  
Luis García Esteban ◽  
Paloma de Palacios ◽  
Francisco García Fernández ◽  
Antonio Guindeo ◽  
Marta Conde ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Pinus Sylvestris ◽  
Integration Method ◽  
Juvenile Wood ◽  
Crystallinity Index ◽  
Isosteric Heat ◽  
Chemical Modifications ◽  
Clapeyron Equation ◽  
X Ray ◽  
Hemicellulose Degradation

Abstract The hygroscopicity and thermodynamic properties of juvenile Pinus sylvestris L. wood taken from the submerged piles of a bridge built in 1903 over the Jiloca River, in Spain, were compared with the corresponding values of juvenile wood of the same species from recently cut trees. The 35°C and 50°C isotherms were plotted and subsequently fitted using the Guggenheim-Anderson-Boer-Dent method, and the isosteric heat of sorption was obtained through the integration method of the Clausius-Clapeyron equation. The isotherms were compared by means of the hysteresis coefficients. Infrared spectra were recorded to study the chemical modifications, and the crystal structure of the cellulose was studied by X-ray diffractograms. The submersion in water resulted in hemicellulose degradation and a decrease in the crystallinity index and the crystallite length, accompanied by a corresponding increase in the proportion of amorphous zones. Owing to this, the equilibrium moisture contents of the water logged wood are higher than in the recent wood, both in adsorption and in desorption. In terms of the thermodynamic properties, the bond energy is higher in the recent wood than in the water logged wood.

scholarly journals Analysis of Energy Characteristics of Rice and Coffee Husks Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Cuthbert F. Mhilu
Keyword(s):  
Thermogravimetric Analysis ◽  
First Generation ◽  
Point Of View ◽  
Rice Husks ◽  
Material Degradation ◽  
Energy Characteristics ◽  
Hemicellulose Degradation ◽  
Active Interest ◽  
Retention Characteristics ◽  
Work Done

Production of first generation biofuels using food crops is under criticism over sustainability issues on food security. Tanzania is showing active interest in developing second generation biofuels to deal with some of such issues, especially from the feedstock point of view. This paper reports work done to determine energy characteristics of rice and coffee husks. The results show that coffee husks have better energy quality than rice husks, while heating values of coffee are 18.34 MJ/kg and 13.24 MJ/kg for rice husk. Thermogravimetric analysis made for coffee husks blended rice husks at a ratio of 75 : 25% vol. show better material degradation characteristics yielding low residual mass of 23.65%, compared to 26.50% of char and ash remaining in pure rice husks. Derivative thermogravimetric analysis shows comparable hemicellulose degradation peak values of −11.5 and −11.2 and cellulose −3.20 and −2.90 in pure coffee and rice husks, respectively. In coffee and rice husks blends, substantial reductions of hemicellulose and cellulose peaks were observed. Use of coffee and rice husks blends applying high temperature gasification would reduce the latter’s flammability, while increasing its flame retention characteristics, hence offering opportunities for production of clean syngas in a sustainable manner.

scholarly journals Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages

2016 ◽  
Vol 30 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Tingting Ning ◽  
Huili Wang ◽  
Mingli Zheng ◽  
Dongze Niu ◽  
Sasa Zuo ◽  
...  
Keyword(s):  
Total Mixed Ration ◽  
Microbial Enzymes ◽  
Hemicellulose Degradation

The localization and activity of Cellulomonas xylanase on sugarcane bagasse pith

1985 ◽  
Vol 31 (8) ◽  
pp. 754-756 ◽  
Author(s):  
H. Rodríguez ◽  
A. Enríquez ◽  
O. Volfová
Keyword(s):  
Sugarcane Bagasse ◽  
Growth Phase ◽  
Xylanase Activity ◽  
Rapid Degradation ◽  
Second Growth ◽  
Hemicellulose Degradation ◽  
Bagasse Pith ◽  
Sugarcane Bagasse Pith

Xylanase activity was found both free and bound to the cells and (or) the substrate during the first growth phase of Cellulomonas on bagasse pith. At the same time, rapid degradation of the bagasse hemicellulose was observed. The enzymes became bound mainly during the second growth phase, during which hemicellulose degradation was still detected, although at a lower rate. Intracellular xylanase activity was about one-tenth of the activity detected outside the cell during this phase. At the end of growth, 89% of the bagasse hemicellulose had been consumed.

INFLUENCE OF PHENOLIC ACIDS ON FORAGE STRUCTURAL CARBOHYDRATE DIGESTION

1984 ◽  
Vol 64 (5) ◽  
pp. 50-51 ◽  
Author(s):  
H. G. JUNG ◽  
G. C. FAHEY JR.
Keyword(s):  
Tall Fescue ◽  
Phenolic Acid ◽  
Acid Content ◽  
Coumaric Acid ◽  
Cellulose Digestion ◽  
Hemicellulose Degradation ◽  
Structural Carbohydrate ◽  
Ferulic Acids ◽  
Carbohydrate Digestion

p-Coumaric acid (PCA) and ferulic acid (FA) inhibit cellulose digestion in vitro, whereas PCA stimulates hemicellulose degradation. Acid concentrations increase in tall fescue during maturation but remain stable in alfalfa. Hemicellulose and cellulose digestion by sheep is associated with phenolic acid content of tall fescue but not of alfalfa. Key words: p-Coumaric and ferulic acids, hemicellulose and cellulose digestion

Within-process and seasonal changes during industrial production of high-density fibreboard. Part 1: Influence of wood species composition on polyoses in the products

Holzforschung ◽  
2012 ◽  
Vol 66 (5) ◽  
pp. 667-672 ◽  
Author(s):  
Martin Weigl ◽  
Rupert Wimmer ◽  
Thomas Ters ◽  
Roland Mitter ◽  
Thomas Kuncinger
Keyword(s):  
Wood Species ◽  
Galacturonic Acid ◽  
Middle Lamella ◽  
Strength Loss ◽  
High Density ◽  
Chemical Degradation ◽  
Structural Alterations ◽  
Compound Middle Lamella ◽  
Hemicellulose Degradation ◽  
Composition Changes

Abstract Industrially produced high-density fibreboard fibres are inhomogeneous in structure and chemical composition. Changes in polysaccharide chemistry during processing have an impact on strength loss, fibre separation and structural alterations. In the present study, carbohydrate composition of extracted wood chips and refiner fibres was monitored for a year at an industrial HDF plant. The polysaccharides were analysed via methanolysis and quantification of the monomeric sugars released. Significant reductions of arabinose, xylose, rhamnose and galacturonic acid were observed. The amount of glucose and extractable substances increased. The depletion of galacturonic acid and rhamnose indicates a degradation of pectin located in the compound middle lamella. The diminishing amounts of the other sugars and elevated extractive contents are a result of hemicellulose degradation. A pronounced seasonal variability of the data was observed depending on the processed wood species and degree of chemical degradation.

An experimental study of cellulose and hemicellulose degradation in the alimentary canal of the American cockroach

1977 ◽  
Vol 55 (3) ◽  
pp. 579-589 ◽  
Author(s):  
D. E. Bignell
Keyword(s):  
Experimental Study ◽  
Alimentary Canal ◽  
American Cockroach ◽  
Artificial Diets ◽  
In Vitro Degradation ◽  
Heat Stable ◽  
Adult Females ◽  
Hemicellulose Degradation ◽  
Important Site

Artificial diets containing [14C]cellulose and [14C]hemicellulose were prepared and fed to adult females. During the first 300 h after ingestion, 14CO2 was recovered equivalent to about 73% (cellulose) and 48% (hemicellulose) of the label ingested. For both polysaccharides the rate of 14CO2 evolution peaked 20–40 h after feeding and label was acquired by hemolymph trehalose. The evolution of 14CO2 from labelled cellulose was sharply reduced when antibiotics were supplied in the diet either with the labelled polysaccharide or before its ingestion. When each polysaccharide was introduced into the lumen of the cannulated colon in vitro, degradation occurred and acid- and heat-stable labelled material appeared in the incubation medium. It is proposed that cellulose and hemicellulose are potentially of nutritional significance in this insect and that the hindgut may be an important site of degradation.

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