The hydrolysis of steamed birchwood hemicellulose by enzymes produced byTrichoderma reesei andAspergillus awamori

Degradation of different [(glucurono)arabino]xylans by a combination of purified xylan-degrading enzymes

“…Wood and McCrae (1986), however, only observed an increase in the rate, but not in the extent of degradation of chemically deacetylated ryegrass cell walls by endo-xylanases and cellulases of T. koningii. A crude preparation of A. awamori was found to be unable to hydrolyse glucuronoxylan-oligosaccharides from steamed birchwood xylan (Poutanen et al 1986). Steamed birchwood xylan, however, was degraded to a large extent by Endo I or III in combination with fl-xylosidase and AE (Table 4).…”

Hydrolysis of different chain length xylooliogmers by cellulase and hemicellulase

“…The cellulose fraction consists of b-1,4-linked glucose units aligned in long crystalline chains that form fibers (Nishiyama et al, 2003;Wada et al, 2008). The hemicellulose content is somewhat less than for cellulose in cellulosic biomass and is mainly made up of hetero-1,4-b-D-xylan (Poutanen et al, 1986). Unlike cellulose, hemicellulose, primarily xylan, is amorphous and highly branched and much easier to thermochemically depolymerize to monomeric sugars with high yields at the low pH of dilute acid pretreatments (Jacobsen and Wyman, 2000;Saha, 2003).…”

Production of a high level of cellulase-free xylanase by the thermophilic fungus Thermomyces lanuginosus in laboratory and pilot scales using lignocellulosic materials

“…The complete breakdown of the xylan requires several different side-branchsplitting enzymes, e.g. a-glucuronidase, acetylxylan esterase, acetyl esterase and a-arabinosidase, in addition to the key enzymes, endo-l,4-/3-xylanase and/3-xylosiCorrespondence to: J. Gomes dase Dekker and Richards 1976;Kormelink et al 1991;Poutanen et al 1986;Puls et al 1987;Smith et al 1991). Therefore, xylanases have potential application in the bioconversion of xylan-containing lignocellulosic materials to sugar, alcohol and other useful products (Wong et al 1988).…”