Preparation method of xylanase or lignin peroxidase and application thereof to industrial bleaching field

The invention discloses a preparation method of xylanase or lignin peroxidase, which comprises the following steps: (1) activating and culturing green Saccharomonospora strain to prepare mother liquor; (2) inoculating the mother liquid obtained in step (1) into Sauton culture medium for inducing to produce enzyme which contains induction substrate for culture; (3) centrifuging the bacteria liquid obtained in step (2) and then collecting clear liquid to obtain the crude extract of the enzyme; and (4) dialyzing the crude extract in step (3), and then carrying out chromatography and purification to obtain theenzyme solution of the xylanase or the lignin peroxidase. The mother liquid obtained in step (1) can be also inoculated into the lignin peroxidase containing the induction substrate prepared by post-fermentation and culture. The xylanase or the lignin peroxidase prepared by the method of the invention has lower cellulase activity, thereby preventing reduction of fiber strength and viscosity of thick liquid i