title: Purification and enzymatic characterization of two beta-endoxylanases from Trichoderma sp. K9301 and their actions in xylooligosaccharide production.
abstract: Trichoderma sp. K9301 secreting endoxylanases with an activity of 2836 U/g (dry weight) was screened for XOs production. Two acidic beta-endoxylanases EX1 (30.1 kDa) and EX2 (20.1 kDa) were purified from crude extract of the strain K9301 in solid fermentation. Action modes of EX1 and EX2 towards XOs showed similar hydrolysis characters to endoxylanases belonging to glycosyl hydrolase family 10 and 11, respectively. EX1 exhibited better affinity but lower hydrolytic efficiency than EX2 to xylans from beechwood, birchwood, and oat-spelt. They had synergistic action on xylan hydrolysis. The optimum condition to prepare XOs from corncobs was obtained as 10 mg/ml corncob xylan incubated with 10 U/mg crude enzymes at 50 degrees C for 3 h. The yield of XOs reached 43.3%, and only a little amount of xylose (3.1%) was simultaneously produced, suggesting the good potential of strain K9301 in XOs production.
authors.affiliation: The State Key Lab of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, PR China.
authors.forename: Lei-Lei
authors.initials: LL
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Dong-Hua
authors.initials: DH
authors.lastname: Zhang
authors.forename: Xiu-Lan
authors.initials: XL
authors.lastname: Chen
authors.forename: Cai-Yun
authors.initials: CY
authors.lastname: Sun
authors.forename: Bai-Cheng
authors.initials: BC
authors.lastname: Zhou
authors.forename: Yu-Zhong
authors.initials: YZ
authors.lastname: Zhang
mesh_terms: D018554:Avena / Q000378:metabolism; D045424:Complex Mixtures / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D043364:Endo-1,4-beta Xylanases / Q000302:isolation & purification*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D013696:Temperature; D013997:Time Factors; D014242:Trichoderma / Q000201:enzymology*; D014990:Xylans / Q000096:biosynthesis*; D003313:Zea mays / Q000378:metabolism
chemical_list: D045424:Complex Mixtures; D014990:Xylans; D043364:Endo-1,4-beta Xylanases