Method for treating dissolving pulp

Abstract

The present invention relates to treatment of dissolving pulp with a lytic polysaccharide monooxygenase. The lytic polysaccharide monooxygenase treatment results in reduced viscosity and/or improved viscosity control in the dissolving pulp production process and/or 5 increased reactivity of the dissolving pulp.

1 . A method for treating dissolving pulp, comprising a step of subjecting the dissolving pulp to a lytic polysaccharide monooxygenase. 
     
     
         2 . The method according to  claim 1 , further comprising a step of subjecting the dissolving pulp to a cellulase, pre:erably an endoglucanase. 
     
     
         3 . The method according to  claim 2 , wherein the step of subjecting the dissolving pulp to a lytic polysaccharide monooxygenase and the step of subjecting the dissolving pulp to a cellulase are carried out simultaneously. 
     
     
         4 . The method according to  claim 1 , further comprising a step of bleaching the dissolving pulp. 
     
     
         5 . The method according to  claim 1 , further comprising a step of subjecting the dissolving pulp to a lytic polysaccharide monooxygenase and an electron donor thereof, preferably ascorbic acid, gallic acid, pyrogallol or cysteine. 
     
     
         6 . The method according to  claim 1 , wherein the dissolving pulp is an alkaline extracted dissolving pulp; kraft pulp or sulfite pulp. 
     
     
         7 . The method according to  claim 1 , wherein the lytic polysaccharide monooxygenase has a sequence identity of at least 60% to the mature polypeptide of SEQ ID NO: 1 and/or to the mature polypeptide of SEQ ID NO: 2 and/or to the mature polypeptide of SEQ ID NO: 3. 
     
     
         8 . The method according to  claim 2 , wherein the cellulase has a sequence identity of at least 60% to SEQ ID NO: 4, and/or to the mature polypeptide of SEQ ID NO: 5, and/or to the mature polypeptide of SEQ ID NO: 6, and/or to the mature polypeptide of SEQ ID NO: 7. 
     
     
         9 . The method according to  claim 1 , wherein the lytic polysaccharide monooxygenase comprises SEQ ID NO: 1 or the mature polypeptide thereof, SEQ ID NO: 2 or the mature polypeptide thereof, or SEQ ID NO: 3 or the mature polypeptide thereof. 
     
     
         10 . The method according to  claim 1 , wherein concentration of the lytic polysaccharide monooxygenase is from 0.05 mg/kg oven dry pulp to 100000 mg/kg oven dry pulp, optionally a concentration selected from the group consisting of from 0.05 mg/kg oven dry pulp to 250 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 1000 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 2000 mg/kg oven dry pulp, from 1.0 mg/kg oven dry pulp to 5000 mg/kg oven dry pulp, from 5.0 mg/kg oven dry pulp to 10000 mg/kg oven dry pulp, from 10.0 mg/kg oven dry pulp to 15000 mg/kg oven dry pulp, from 15.0 mg/kg oven dry pulp to 20000 mg/kg oven dry pulp, from 20.0 mg/kg oven dry pulp to 30000 mg/kg oven dry pulp, from 30.0 mg/kg oven dry pulp to 40000 mg/kg oven dry pulp, from 40.0 mg/kg oven dry pulp to 60000 mg/kg oven dry pulp, from 60.0 mg/kg oven dry pulp to 80000 mg/kg oven dry pulp, and from 80.0 mg/kg oven dry pulp to 100000 mg/kg oven dry pulp, or any combination of these intervals. 
     
     
         11 . The method according to  claim 2 , wherein concentration of the cellulase is from 0.05 mg/kg oven dry pulp to 100 mg/kg oven dry pulp, optionally a concentration selected from the group consisting of from 0.05 mg/kg oven dry pulp to 80.0 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 60.0 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 40.0 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 20.0 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 10.0 mg/kg oven dry pulp, from 0.25 mg/kg oven dry pulp to 5.0 mg/kg oven dry pulp, from 0.50 mg/kg oven dry pulp to 85.0 mg/kg oven dry pulp, from 0.50 mg/kg oven dry pulp to 65.0 mg/kg oven dry pulp, from 0.50 mg/kg oven dry pulp to 45.0 mg/kg oven dry pulp, from 0.50 mg/kg oven dry pulp to 25.0 mg/kg oven dry pulp, from 0.50 mg/kg oven dry pulp to 15.0 mg/kg oven dry pulp and from 0.50 mg/kg oven dry pulp to 5.0 mg/kg oven dry pulp or any combination of these intervals. 
     
     
         12 . The method according to  claim 1 , wherein the method results in reduced viscosity and/or mproved viscosity control in the dissolving pulp production process; and/or wherein the method results in increased reactivity of the dissolving pulp, preferably increased Fock's reactivity; and/or wherein the method results in increased content of oxidized groups of the dissolving pulp. 
     
     
         13 . The method according to  claim 1 , further comprising a step of subjecting the dissolving pulp to a xylanase and/or a mannanase and/or a lipase and/or laccase and/or peroxidase. 
     
     
         14 . A dissolving pulp made by the method according to  claim 1 . 
     
     
         15 . A textile fiber or a derivatized cellulose made of the dissolving pulp according to  claim 14 . 
     
     
         16 . (canceled) 
     
     
         17 . The method according to  claim 2 , wherein the step of subjecting the dissolving pulp to a lytic polysaccharide monooxygenase and the step of subjecting the dissolving pulp to a cellulase are carried out sequentially. 
     
     
         18 . The method according to  claim 2  wherein the cellulase comprises SEQ ID NO; 4 of the mature polypeptide thereof, SEQ ID NO: 5 or the mature polypeptide thereof, SEQ ID NO: 6 or the mature polypeptide thereof, or SEQ ID NO: 7 or the mature polypeptide thereof.