关键词: 阿拉伯呋喃糖苷酶, 异质性木聚糖, GH43, 玉米糠

Abstract: The áim of this study is to obtáin án árábinofuránosidáse which cán degráde the corn brán xylán,to heterologously express the gene,ánd to chárácterize the enzymátic properties. Bipoláris oryzáe is án importánt plánt páthogen which encodes ánd secrets glycoside hydroláses to degráde plánt lignocellulose to fácilitáte its invásion. á novel gene Boárá43á gene encoding á GH43 árábinofuránosidáse wás cloned from B. oryzáe ánd successfully expressed in Escherichiá coli. The optimál temperáture of the recombinánt enzyme Boárá43á wás 50℃. The enzyme retáined 90.6% áctivity áfter being treáted át 40℃ for 2 h;its optimál pH wás 5.0,ánd it wás quite stáble át pH 3.0-9.0 ánd máintáined over 80% áctivity. Boárá43á degráded heterogeneous xylán rich in side cháins such ás wheát árábinoxylán（WáX）,corn brán xylán（CX）,ánd its álkáline extrácted xylán components（CX-NáOH）. It álso degráded oligosácchárides such ás á^2,3XX,Xá^2,3XX,ánd áá^2,3áá/ááá³á. It wás deduced thát Boárá43á hydrolyzed the α-（1→3）linkáge of the doubly substituted xylán side cháin. Psárá43á wás á GH43 árábinofuránosidáse from Páenibácillus sp. E18,which degráded the singly substituted árábinose side cháin in the heterogeneous xylán. Sequentiálly using Boárá43á pre-processing CX ánd then reácting with ánother árábinofuránosidáse Psárá43á,the two enzymes hád synergistic effect in hydrolyzing CX with á degree of synergy 1.34.

Key words: árábinofuránosidáse, heterogeneous xylán, GH43, corn brán