Bio-bleaching of pulp using laccase, mediator, and chain transfer agent

Abstract

A process of oxidizing a substrate is disclosed. The process comprising the step of treating the substrate with an oxidizing enzyme, a mediator that enhances the oxidative activity of the enzyme, and a chain transfer agent. In one example, the substrate is a lignin-containing material and the process results in bleaching of the lignin-containing material. Examples of some useful enzymes are laccase, catechol oxidase, monophenol monooxygenase, and bilirubin oxidase. A composition comprising an oxidative enzyme, a mediator that enhances the oxidative activity of the enzyme, and a chain transfer agent is also disclosed.

What is claimed is:  
     
         1 . A process for bleaching a lignin-containing material comprising treating the material with an oxidative enzyme, a mediator that enhances the oxidative activity of said enzyme, and a chain transfer agent.  
     
     
         2 . The process of  claim 1  wherein said enzyme has laccase activity.  
     
     
         3 . The process of  claim 1  wherein said oxidative enzyme is a laccase, a catechol oxidase, a monophenol monooxygenase, a bilirubin oxidase, or a mixture thereof.  
     
     
         4 . The process of  claim 1  that further comprises adding a hydrolase.  
     
     
         5 . The process of  claim 3  wherein said hydrolase is xylanase.  
     
     
         6 . The process of  claim 1  that further comprises adding an oxidizing agent.  
     
     
         7 . The process of  claim 6  wherein said oxidizing agent comprises at least one of air, oxygen, and hydrogen peroxide.  
     
     
         8 . The process of  claim 1  wherein said mediator is a hardwood black liquor or a softwood black liquor.  
     
     
         9 . The process of  claim 1  wherein said chain transfer agent is anthracene, carbon tetrabromide, or a mixture thereof.  
     
     
         10 . The process of  claim 1  wherein said material is a wood pulp.  
     
     
         11 . The process of  claim 10  wherein said wood pulp is a raw material used to form a cellulose or a cellulose derivative.  
     
     
         12 . A process for oxidizing a substrate comprising treating the substrate with an oxidizing enzyme, a mediator that enhances the oxidative activity of said enzyme, and a chain transfer agent.  
     
     
         13 . The process of  claim 12  wherein said oxidizing enzyme is a laccase, a catechol oxidase, a monophenol monooxygenase, a bilirubin oxidase, or a mixture thereof.  
     
     
         14 . The process of  claim 12  that further comprises adding an oxidizing agent.  
     
     
         15 . The process of  claim 14  wherein said oxidizing agent comprises at least one of air, oxygen, and hydrogen peroxide.  
     
     
         16 . The process of  claim 12  wherein said mediator is a hardwood black liquor or a softwood black liquor.  
     
     
         17 . The process of  claim 12  wherein said chain transfer agent is anthracene, carbon tetrabromide, or a mixture thereof.  
     
     
         18 . The process of  claim 12  that further comprises adding an oxidizing agent.  
     
     
         19 . The process of  claim 18  wherein said oxidizing agent comprises at least one of air, oxygen, and hydrogen peroxide.  
     
     
         20 . A composition comprising an oxidative enzyme, a mediator that enhances the oxidative activity of said enzyme, and a chain transfer agent.  
     
     
         21 . The composition of  claim 20  wherein said enzyme has laccase activity.  
     
     
         22 . The composition of  claim 20  wherein said oxidative enzyme is a laccase, a catechol oxidase, a monophenol monooxygenase, a bilirubin oxidase, or a mixture thereof.  
     
     
         23 . The composition of  claim 20  that further comprises adding a hydrolase.  
     
     
         24 . The composition of  claim 20  wherein said hydrolase is xylanase.  
     
     
         25 . The composition of  claim 20  wherein said chain transfer agent is anthracene, carbon tetrabromide, or a mixture thereof.