Process and composition for preparing a lignocellulose-based product, and the product obtained by the process

Abstract

A process for the manufacture of a lignocellulose product, the process comprising the step of mixing in a reaction medium (i) a phenolic polymer being substituted with a phenolic hydroxy group; (ii) a lignocellulose containing material having immobilized to a cellulosic fraction thereof a fusion polypeptide, the fusion polypeptide including an enzyme being capable of catalyzing the oxidation of phenolic groups and a cellulose binding peptide; and (iii) an oxidizing agent. A composition of matter for use in the process and a lignocellulose product obtainable by the process are also disclosed.

1 . A process for the manufacture of a lignocellulose product, the process comprising the step of mixing in a reaction medium: 
 (i) a phenolic polymer being substituted with a phenolic hydroxy group;    (ii) a lignocellulose containing material having immobilized to a cellulosic fraction thereof a fusion polypeptide, said fusion polypeptide including an enzyme being capable of catalyzing the oxidation of phenolic groups and a cellulose binding peptide; and    (iii) an oxidizing agent.    
   
   
       2 . The process of  claim 1 , wherein said lignocellulose product is selected from the group consisting of fiber board, particle board, flakeboard, plywood and molded composites.  
   
   
       3 . The process of  claim 1 , wherein said lignocellulose product is selected from the group consisting of paper and paperboard.  
   
   
       4 . The process of  claim 1 , wherein said lignocellulose containing material is a cell wall preparation derived from a genetically modified or virus infected plant or cultured plant cells expressing said fusion protein.  
   
   
       5 . The process of  claim 1 , wherein said lignocellulose containing material is selected from the group consisting of vegetable fiber and wood fiber derived from a genetically modified or virus infected plant expressing said fusion polypeptide.  
   
   
       6 . The process of  claim 1 , wherein the phenolic substituent is selected from the group consisting of p-coumaric acid, p-coumaryl alcohol, coniferyl alcohol, sinapyl alcohol, ferulic acid and p-hydroxybenzoic acid.  
   
   
       7 . The process of  claim 1 , wherein said phenolic polymer forms an integral part of said lignocellulose containing material.  
   
   
       8 . The process of  claim 7 , wherein said phenolic polymer is lignin.  
   
   
       9 . The process of  claim 1 , wherein said phenolic polymer is a phenolic polysaccharide.  
   
   
       10 . The process of  claim 9 , wherein the polysaccharide portion of the phenolic polysaccharide is selected from the group consisting of modified and unmodified starches, modified and unmodified cellulose, and modified and unmodified hemicelluloses.  
   
   
       11 . The process of  claim 9 , wherein said phenolic polysaccharide is selected from the group consisting of ferulylated arabinoxylans and ferulylated pectins.  
   
   
       12 . The process of  claim 1 , wherein said reaction medium is incubated for a period of from 1 minute to 10 hours.  
   
   
       13 . The process of  claim 12 , wherein said fusion polypeptide is incubated in the presence of said oxidizing agent for a period of from 1 minute to 10 hours.  
   
   
       14 . The process of  claim 1 , wherein said enzyme is selected from the group consisting of oxidases and peroxidases.  
   
   
       15 . The process of  claim 1 , wherein said enzyme is an oxidase selected from the group consisting of laccases (EC 1.10.3.2), catechol oxidases (EC 1.10.3.1) and bilirubin oxidases (EC 1.3.3.5), and said oxidizing agent is oxygen.  
   
   
       16 . The process of  claim 15 , wherein said enzyme is a laccase and is present in an amount in the range of 0.02-2000 LACU per g of dry lignocellulose.  
   
   
       17 . The process of  claim 15 , wherein said reaction medium is aerated.  
   
   
       18 . The process of  claim 15 , wherein said enzyme is a laccase encoded by a polynucleotide obtained from a fungus of the genus  Botrytis, Myceliophthora, Trametes  or the plant  Acer pseudoplanus.    
   
   
       19 . The process of  claim 18 , wherein the fungus is  Trametes versicolor  or  Trametes villosa.    
   
   
       20 . The process of  claim 1 , wherein said enzyme is a peroxidase and said oxidizing agent is hydrogen peroxide.  
   
   
       21 . The process of  claim 20 , wherein said peroxidase is present in an amount in the range of 0.02-2000 PODU per g of dry lignocellulose, and the initial concentration of hydrogen peroxide in the reaction medium is in the range of 0.01-100 mM.  
   
   
       22 . The process of  claim 1 , wherein the amount of lignocellulose employed corresponds to 0.1-90% by weight of the reaction medium, calculated as dry lignocellulose.  
   
   
       23 . The process of  claim 1 , wherein the temperature of the reaction medium is in the range of 10°-120° C.  
   
   
       24 . The process of  claim 23 , wherein the temperature of the reaction medium is in the range of 15°-90° C.  
   
   
       25 . The process of  claim 1 , wherein an amount of said phenolic polymer in the range of 0.1%-10% by weight.  
   
   
       26 . The process of  claim 1 , wherein the pH in the reaction medium is in the range of 3-10.  
   
   
       27 . The process of  claim 26 , wherein the pH in the reaction medium is in the range of 4-9.  
   
   
       28 . The process of  claim 1 , wherein the reaction medium further comprising a lignocellulose containing material devoid of said fusion protein.  
   
   
       29 . The process of  claim 28 , wherein said lignocellulose containing material devoid of said fusion protein is selected from the group consisting of vegetable fiber, wood fiber, wood chips, wood flakes, wood veneer and recycled fibers.  
   
   
       30 . A lignocellulose product obtainable by the process of  claim 1 .  
   
   
       31 . A genetically modified or viral infected plant or cultured plant cells expressing a fusion protein including an enzyme being capable of catalyzing the oxidation of phenolic groups and a cellulose binding peptide.  
   
   
       32 . The genetically modified or viral infected plant or cultured plant cells of  claim 31 , wherein said fusion protein being compartmentalized within cells of said plant or cultured plant cells, so as to be sequestered from cell walls of said cells of said plant or cultured plant cells.  
   
   
       33 . The genetically modified or viral infected plant or cultured plant cells of  claim 31 , wherein expression of said fusion protein is under a control of a constitutive or tissue specific plant promoter.  
   
   
       34 . The genetically modified or viral infected plant or cultured plant cells of  claim 32 , wherein said fusion protein is compartmentalized within a cellular compartment selected from the group consisting of cytoplasm, endoplasmic reticulum, golgi apparatus, oil bodies, starch bodies, chloroplastids, chloroplasts, chromoplastids, chromoplasts, vacuole, lysosomes, mitochondria, and nucleus.  
   
   
       35 . A composition of matter comprising a cell wall preparation derived from a genetically modified or virus infected plant or cultured plant cells expressing a fusion protein including an enzyme being capable of catalyzing the oxidation of phenolic groups and a cellulose binding peptide, said fusion protein being immobilized to cellulose in said cell wall preparation via said cellulose binding peptide.  
   
   
       36 . A nucleic acid molecule comprising: 
 (a) a promoter sequence for directing protein expression in plant cells; and    (b) a heterologous nucleic acid sequence including: 
 (i) a first sequence encoding a cellulose binding peptide;  
 (ii) a second sequence encoding an enzyme being capable of catalyzing the oxidation of phenolic groups, wherein said first and second sequences are joined together in frame.  
   
   
   
       37 . The nucleic acid molecule of  claim 36 , further comprising a sequence element selected from the group consisting of an origin of replication for propagation in bacterial cells, at least one sequence element for integration into a plant's genome, a polyadenylation recognition sequence, a transcription termination signal, a sequence encoding a translation start site, a sequence encoding a translation stop site, plant RNA virus derived sequences, plant DNA virus derived sequences, tumor inducing (Ti) plasmid derived sequences, a transposable element derived sequence and a plant operative signal peptide for directing a protein to a cellular compartment of a plant cell.  
   
   
       38 . The nucleic acid molecule of  claim 36 , wherein said cellular compartment is selected from the group consisting of cytoplasm, endoplasmic reticulum, golgi apparatus, oil bodies, starch bodies, chloroplastids, chloroplasts, chromoplastids, chromoplasts, vacuole, lysosomes, mitochondria, and nucleus.