Laccase activity enhancers for pulp bleaching

Abstract

A composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent, also referred to as a mediator, is disclosed. A process for oxidizing a substrate that comprises treating the substrate with a composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent is disclosed. The process when used on lignin-containing material bleaches the lignin-containing material. A process for enhancing the activity of an enzyme exhibiting laccase activity that comprises adding an enzyme enhancing agent to the enzyme is also disclosed.

What is claimed is:  
     
         1 . A composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent selected from 2-thiouracil, sodium dimethyldithio carbonate hydrate, N-benzylidene-benzylamine, melamine, anthracene, dicyandiamide, sulfanilic acid, sulfanilamide,urea, salicylic acid, 3,4,5-trihydroxy-benzoic acid, ferric chloride, potassium ferricyanide, ascorbic acid, Zincon (o-[2-[alpha(2-hydroxy-5-sulfophenylazo)benzylidene]hydrazino]benzoic acid), diisopropanolamine, adenosine triphosphate, guanidine, cyanuric acid, Thiazol Yellow G, nicotinic acid, Metanil Yellow, hardwood black liquor, softwood black liquor, methanesulfonic acid, metanilic acid, sulfamide, 3-pyridine sulfonic acid, benzofuroxan, t-butyl hydroperoxide, pyruvic acid, imidazole, N-acetylcytosine, and phenol.  
     
     
         2 . The composition of  claim 1  wherein said enzyme exhibiting laccase activity is selected from a laccase enzyme of enzyme classification EC 1.10.3.2, a catechol oxidase enzyme of enzyme classification EC 1.10.3.1, a monophenol monooxygenase enzyme of enzyme classification EC 1.14.99.1, a bilirubin oxidase enzyme of enzyme classification EC 1.3.3.5, and an ascorbate oxidase enzyme of enzyme classification EC 1.10.3.3.  
     
     
         3 . The composition of  claim 1  that further comprises a hydrolase.  
     
     
         4 . The composition of  claim 3  wherein said hydrolase is a xylanase.  
     
     
         5 . A process for oxidizing a substrate, comprising treating the substrate with a composition comprising an enzyme exhibiting laccase activity and an enzyme enhancing agent selected from 2-thiouracil, sodium dimethyldithio carbonate hydrate, N-benzylidene-benzylamine, melamine, anthracene, dicyandiamide, sulfanilic acid, sulfanilamide,urea, salicylic acid, 3,4,5-trihydroxy-benzoic acid, ferric chloride, potassium ferricyanide, ascorbic acid, Zincon (o-[2-[alpha(2-hydroxy-5-sulfophenylazo)benzylidene]hydrazino]benzoic acid), diisopropanolamine, adenosine triphosphate, guanidine, cyanuric acid, Thiazol Yellow G, nicotinic acid, Metanil Yellow, hardwood black liquor, softwood black liquor, methanesulfonic acid, metanilic acid, sulfamide, 3-pyridine sulfonic acid, benzofuroxan, t-butyl hydroperoxide, pyruvic acid, imidazole, N-acetylcytosine, and phenol.  
     
     
         6 . The process of  claim 5  wherein said enzyme exhibiting laccase activity is selected from a laccase enzyme of enzyme classification EC 1.10.3.2, a catechol oxidase enzyme of enzyme classification EC 1.10.3.1, a monophenol monooxygenase enzyme of enzyme classification EC 1.14.99.1, a bilirubin oxidase enzyme of enzyme classification EC 1.3.3.5, and an ascorbate oxidase enzyme of enzyme classification EC 1.10.3.3.  
     
     
         7 . The process of  claim 5  wherein said treating further includes a hydrolase.  
     
     
         8 . The process of  claim 7  wherein said hydrolase is a xylanase.  
     
     
         9 . The process of  claim 5  that further comprises adding an oxidizing agent.  
     
     
         10 . The process of  claim 9  wherein said oxidizing agent is at least one of air, oxygen, and hydrogen peroxide.  
     
     
         11 . A process for bleaching a lignin-containing material, comprising treating the material with an enzyme exhibiting laccase activity and an enzyme enhancing agent selected from 2-thiouracil, sodium dimethyldithio carbonate hydrate, N-benzylidene-benzylamine, melamine, anthracene, dicyandiamide, sulfanilic acid, sulfanilamide,urea, salicylic acid, 3,4,5-trihydroxy-benzoic acid, ferric chloride, potassium ferricyanide, ascorbic acid, Zincon (o-[2-[alpha(2-hydroxy-5-sulfophenylazo)benzylidene]hydrazino]benzoic acid), diisopropanolamine, adenosine triphosphate, guanidine, cyanuric acid, Thiazol Yellow G, nicotinic acid, Metanil Yellow, hardwood black liquor, softwood black liquor, methanesulfonic acid, metanilic acid, sulfamide, 3-pyridine sulfonic acid, benzofuroxan, t-butyl hydroperoxide, pyruvic acid, imidazole, N-acetylcytosine, and phenol.  
     
     
         12 . The process of  claim 11  wherein said enzyme exhibiting laccase activity is selected from a laccase enzyme of enzyme classification EC 1.10.3.2, a catechol oxidase enzyme of enzyme classification EC 1.10.3.1, a monophenol monooxygenase enzyme of enzyme classification EC 1.14.99.1, a bilirubin oxidase enzyme of enzyme classification EC 1.3.3.5, and an ascorbate oxidase enzyme of enzyme classification EC 1.10.3.3.  
     
     
         13 . The process of  claim 11  wherein said treating further includes a hydrolase.  
     
     
         14 . The process of  claim 13  wherein said hydrolase is a xylanase.  
     
     
         15 . The process of  claim 11  that further comprises adding an oxidizing agent.  
     
     
         16 . The process of  claim 15  wherein said oxidizing agent is at least one of air, oxygen, and hydrogen peroxide.  
     
     
         17 . The process of  claim 11  wherein said material is a wood pulp.  
     
     
         18 . The process of  claim 17  wherein said wood pulp is a raw material used to form a polysaccharide or a cellulose derivative.  
     
     
         19 . A process for enhancing the activity of an enzyme exhibiting laccase activity, comprising adding an enzyme enhancing agent to said enzyme, wherein said enzyme enhancing agent is selected from 2-thiouracil, sodium dimethyldithio carbonate hydrate, N-benzylidene-benzylamine, melamine, anthracene, dicyandiamide, sulfanilic acid, sulfanilamide,urea, salicylic acid, 3,4,5-trihydroxy-benzoic acid, ferric chloride, potassium ferricyanide, ascorbic acid, Zincon (o-[2-[alpha(2-hydroxy-5-sulfophenylazo)benzylidene]hydrazino]benzoic acid), diisopropanolamine, adenosine triphosphate, guanidine, cyanuric acid, Thiazol Yellow G, nicotinic acid, Metanil Yellow, hardwood black liquor, softwood black liquor, methanesulfonic acid, metanilic acid, sulfamide, 3-pyridine sulfonic acid, benzofuroxan, t-butyl hydroperoxide, pyruvic acid, imidazole, N-acetylcytosine, and phenol.