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

Abstract

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 in the process of enzyme processing; and the prepared xylanase or the lignin peroxidase has certain heat-resistance and alkali resistance, can directly and effectively attack lignin and degrade hemicellulose, is applicable to pre-bleaching paper pulp in industrial production, and has excellent bleaching effect.

Description

technical field [0001] The invention belongs to the field of biological bleaching materials, and in particular relates to a method for preparing xylanase and lignin peroxidase by using Saccharomonas viridans and its application in the field of industrial bleaching. Background technique [0002] Pulp bleaching is an essential step in the paper industry. During the chemical or mechanical pulping process, about 90% of the lignin can be removed from the cellulose fibers of wood or other coarse raw materials, but 10% remains. This part of the residual lignin will cause the pulp to be brown and reduce the Strength of paper (Chen Jiachuan et al., 1999). In order to bleach the pulp, the residual lignin must be removed. The traditional method is to use acid bleaching agents such as chlorine, chlorine dioxide, etc. to remove lignin. However, this method will make the papermaking wastewater contain a large amount of refractory and toxic , strong carcinogenic and teratogenic organic c...

AI Technical Summary

Problems solved by technology

However, the research on extracellular enzymes produced by actinomycetes mainly focuses on xylanase, and in the study of lignin peroxidase, there are only a few literatures reporting its secretion and production mechanism, fermentation conditions, partial purification and evaluation of its role in xylanase. Potential use in lignocellulose degradation, compared with the study of lignin degrading enzymes secreted by white rot fungi, the purification and identification of lignin peroxidase derived from actinomycetes, as well as the research report on the molecular mechanism of lignin degradation Less (Sunna A and Antranikian G, 1997)

There are no reports on the secretion of extracellular enzymes from S. viridans, especially lignin peroxidase, and there is no study on the purification and characteristics of S. viridans lignin peroxidase

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