| β -mannanase, a kind of endohydrolases, belongs to the hemicellulases. It catalyzes the hydrolysis of the β-1,4 glycosidic linkages within the main chain of β-1,4-mannans including ,galactomannan, glucomannan, galactoglucomannan and mannan, and yielding monosaccharides and oligosaccharides. With exploitation of the resources of hemicellulose and discovery of pharmaccutical value in mannan oligosaccharides, the study of β -mannanase enter a new high tide. They could find applications in food, feed, pharmaccutical, biotechnology, paper and pulp industy and so on. So, it is very important to find high activity or recombined high-level expression β -mannanase. A.tabscens EJLY2098 is a fungus of Tficholomataceae, it is parasitism on the body or root of tree, and can cause many tree's decayed diseases.we use konjac to induce A.tabescens EJLY2098 secreting β -mannanase and screening on plate. It is firstly to find that A.tabescens EJLY2098 can produce β -mannanase. A 34 orthogonal design was applied to determine the optimum medium of inducing β -mannanase.The results suggested that A.tabescens EJLY2098 secreted the high activity enzyme by the optimum medium, which composed of 2% konjac, 1% peptone, 25% potato juice., 0.3% KH2PO4,15% MgSO4.7H2O, 0.01% VitB1. Purified by DEAE-anion exchange chromatography, two eluting peaks( P1 and P2 )had activity of β -mannanase were obtained, and one of them(named β -mannanase P2) was a single band on the SDS-PAGE, and the molecular weight of β-mannanase P2 was 78.9kD.The isoelectric point of β -mannanase P2 was estimated to be 4.0～4.1. The optimum activity for the enzyme was found at 60°C and pH4.0～6.0, and the enzyme was stable between pH4.5～6.0. The activity of β -mannanase P2 were enhanced by Na+ and Ba2+.This β -mannanase can be used in feed industy.Quantity, activity and cost of producing the enzyme in A.tabscens EJLY2098 are the factors limited large-scale producing β -mannanase in industry. Just by using the...
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