Aspergillus xylanase enzyme from

Many examples of the purification of xylanase enzymes to homogeneity can be found in the reviews of Dekker and Richards (85), Woodward (86) and Reilly (87). Other xylanases which have been prepared recently to very high purity using traditional biochemical techniques include xylanases from Sporotrichum dimorphosporum (88) Streptomyces sp. (71) Trichoderma harzianum (5,55) Clostridium acetobuiylicum (30,89) mesophilic fungal strain Y-94 (80) Aspergillus nigcr (90-92) and several thermostable xylanases discussed above. 

Feruloyl esterase activity was first detected in culture filtrates of Strepto-myces olivochromogenes (49), and has thereafter also been reported for some hemicellulolytic fungi (Table III). A partially purified feruloyl esterase from S. commune liberated hardly any ferulic acid without the presence of xylanase (65). Very recently a feruloyl esterase was purified from Aspergillus oryzae (Tenkanen, M. Schuseil, J. Puls, J. Poutanen, K., /. Biotechnol, in press). The enzyme is an acidic monomeric protein having an isoelectric point of 3.6 and a molecular weight of 30 kDa. It has wide substrate specificity, liberating ferulic, p-coumaric, and acetic acids from steam-extracted wheat straw arabinoxylan. 

Enzymes. The mannanase was isolated from Aspergillus niger (11) fraction 4 b was used throughout the experiments (cf. Table 1 in (11)). The xylanase 2, the avicelase 1, and the avicelase 2 were isolated from Trichoderma viride (10). The properties of these enzymes have also been described in the papers cited above. The cellobiohydrolase C was kindly supplied by Dr. R. D. Brown, Jr., and Dr. E. K. Gum, Jr. (Virginia Polytechnic Institute, Blacksburg). The isolation (from Trichoderma viride) and the properties of the cellobiohydrolase C are described in their 1974 paper (12). 

D-Xylanases have been reported to be produced by several strains of bacteria from marine environments,140,141 such as sea water and marine-bottom sediments, and by green, brown, and red algae (seaweeds). The enzymes have also been isolated from terrestrial fungi, for example, Aspergillus batatae,142 Chaetomium globosum,142 and Irpex lacteus.143 These bacteria and fungi were found to produce both (1 -> 3)- and (1 - 4)-/3-D-xylanases, which were secreted extracellularly. 

A comparison of the properties and mode of action of several arabinose-liberating xylanases is summarized in Table XXV it indicates that each enzyme is different from the others. Aspergillus niger van Tieghem D-xylanases II and III (Refs. 172 and 247) failed... 

Eor xylanases the source of the enzyme is important, fungal xylanases from Aspergillus spp. are generally very useful for bread making whereas for cookies Trichoderma spp. xylanases are required because of the differing requirements for water release. 

Extra- and intracellular glycan hydrolases were isolated from Aspergillus flavus and partially characterized both preparations exhibited /3-D-galactanase activity (see p. 499). Gel chromatography of the extracellular enzyme preparation revealed one protein fraction containing jS-D-galactanase activity and a second one exhibiting mainly (3-D-xylanase activity. 

---