Mesoporous catalysts of magnetic nanoparticles and free-radical-producing enzymes, and methods of use

Abstract

A composition comprising mesoporous aggregates of magnetic nanoparticles and free-radical producing enzyme (i.e., enzyme-bound mesoporous aggregates), wherein the mesoporous aggregates of magnetic nanoparticles have mesopores in which the free-radical-producing enzyme is embedded. Methods for synthesizing the enzyme-bound mesoporous aggregates are also described. Processes that use said enzyme-bound mesoporous aggregates for depolymerizing lignin, removing aromatic contaminants from water, and polymerizing monomers polymerizable by a free-radical reaction are also described.

What is claimed is: 
     
         1 . A composition comprising mesoporous aggregates of magnetic nanoparticles and free-radical producing enzyme, wherein said mesoporous aggregates of magnetic nanoparticles have mesopores in which said free-radical-producing enzyme is embedded. 
     
     
         2 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles have an iron oxide composition. 
     
     
         3 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles have a magnetic nanoparticle size distribution in which at least 90% of magnetic nanoparticles have a size of at least 3 nm and up to 30 nm, and an aggregated particle size distribution in which at least 90% of said mesoporous aggregates of magnetic nanoparticles have a size of at least 10 nm and up to 500 nm. 
     
     
         4 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles possess a saturated magnetization of at least 10 emu/g. 
     
     
         5 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles possess a remanent magnetization up to 5 emu/g. 
     
     
         6 . The composition of  claim 1 , wherein said free-radical-producing enzyme is contained in said mesoporous aggregates of magnetic nanoparticles in up to 100% of saturation capacity. 
     
     
         7 . The composition of  claim 1 , wherein said free-radical-producing enzyme is selected from EC 1.11 oxidoreductases acting with peroxide as an acceptor and EC 1.10 oxidoreductases acting on diphenols and related substances as donors, and combinations thereof. 
     
     
         8 . The composition of  claim 7 , wherein said free-radical-producing enzyme is comprised of a peroxidase. 
     
     
         9 . The composition of  claim 8 , wherein said peroxidase is a class II peroxidase. 
     
     
         10 . The composition of  claim 9 , wherein said class II peroxidase is a class II microbial peroxidase. 
     
     
         11 . The composition of  claim 10 , wherein said class II microbial peroxidase is selected from lignin peroxidase, manganese peroxidase, and versatile peroxidase. 
     
     
         12 . The composition of  claim 8 , wherein said peroxidase is a class III peroxidase. 
     
     
         13 . The composition of  claim 12 , wherein said class III peroxidase is selected from horseradish peroxidase, peanut peroxidase, soybean peroxidase, turnip peroxidase, tobacco peroxidase, tomato peroxidase, and barley peroxidase. 
     
     
         14 . The composition of  claim 7 , wherein said free-radical-producing enzyme is a laccase. 
     
     
         15 . The composition of  claim 1 , wherein said mesopores are characterized by a pore size distribution in which at least 90% of the pore volume is attributed to pores having a pore size of at least 2 nm and up to 20 nm. 
     
     
         16 . The composition of  claim 1 , wherein said free-radical-producing enzyme is comprised of an EC 1.1.3 enzyme and a peroxidase. 
     
     
         17 . The composition of  claim 16 , wherein said EC 1.1.3 enzyme is glucose oxidase EC 1.1.3.4. 
     
     
         18 . The composition of  claim 16 , wherein said peroxidase is horseradish peroxidase. 
     
     
         19 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles and free-radical producing enzyme are surface-coated with gold. 
     
     
         20 . The composition of  claim 1 , wherein said mesoporous aggregates of magnetic nanoparticles and free-radical producing enzyme reside on the surface of ferromagnetic submicrometric particles having a size of at least 20 nanometers. 
     
     
         21 . A composition comprising magnetic nanoparticles bound to free-radical-producing enzyme, wherein said magnetic nanoparticles bound to free-radical-producing enzyme are surface-coated with gold. 
     
     
         22 . A composition comprising magnetic nanoparticles bound to free-radical-producing enzyme, wherein said magnetic nanoparticles bound to free-radical-producing enzyme reside on the surface of ferromagnetic submicrometric particles having a size of at least 20 nanometers. 
     
     
         23 . A process for depolymerizing lignin, the method comprising reacting lignin-containing material with a composition comprising magnetic nanoparticles bound to free-radical-producing enzyme to produce depolymerized products from said lignin. 
     
     
         24 . The process of  claim 23 , wherein said depolymerized products are selected from coniferyl, sinapyl, and coumaryl alcohols, and derivatives thereof. 
     
     
         25 . The process of  claim 23 , wherein said free-radical-producing enzyme is comprised of a peroxidase. 
     
     
         26 . The process of  claim 25 , wherein said peroxidase is a lignin-degrading peroxidase. 
     
     
         27 . The process of  claim 26 , wherein said lignin-degrading peroxidase is selected from a lignin peroxidase, versatile peroxidase, manganese peroxidase, and combinations thereof. 
     
     
         28 . The process of  claim 23 , wherein said process is coupled with a lignocellulosic conversion process in which said lignin to be depolymerized is produced by said lignocellulosic material conversion process. 
     
     
         29 . The process of  claim 23 , wherein said magnetic nanoparticles are comprised of mesoporous aggregates of magnetic nanoparticles, wherein said mesoporous aggregates of magnetic nanoparticles have mesopores in which free-radical-producing enzyme is embedded. 
     
     
         30 . The process of  claim 23 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are surface-coated with gold. 
     
     
         31 . The process of  claim 23 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme reside on the surface of ferromagnetic submicrometric particles having a size of at least 20 nanometers. 
     
     
         32 . The process of  claim 23 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are captured by magnetic separation after said process and re-used after being captured, wherein said magnetic nanoparticles bound to free-radical-producing enzyme substantially retain their activity after being captured and re-used. 
     
     
         33 . A process for removing aromatic contaminants from water, the method comprising contacting water contaminated with aromatic substances with a composition comprising magnetic nanoparticles bound to free-radical-producing enzyme to remove said aromatic contaminants from said water. 
     
     
         34 . The process of  claim 33 , wherein contacting said water with said magnetic nanoparticles bound to free-radical-producing enzyme results in precipitation of an insoluble material derived from said aromatic contaminants. 
     
     
         35 . The process of  claim 34 , further comprising removing said insoluble material from said water. 
     
     
         36 . The process of  claim 33 , wherein said aromatic contaminants are comprised of phenolic substances. 
     
     
         37 . The process of  claim 33 , wherein said free-radical-producing enzyme is comprised of a peroxidase. 
     
     
         38 . The process of  claim 33 , wherein said magnetic nanoparticles are comprised of mesoporous aggregates of magnetic nanoparticles, wherein said mesoporous aggregates of magnetic nanoparticles have mesopores in which free-radical-producing enzyme is embedded. 
     
     
         39 . The process of  claim 33 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are surface-coated with gold. 
     
     
         40 . The process of  claim 33 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme reside on the surface of ferromagnetic submicrometric particles having a size of at least 20 nanometers. 
     
     
         41 . The process of  claim 33 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are captured by magnetic separation after said process and re-used after being captured, wherein said magnetic nanoparticles bound to free-radical-producing enzyme substantially retain their activity after being captured and re-used. 
     
     
         42 . A process for polymerizing monomers polymerizable by a free-radical reaction, the method comprising reacting said monomers with a composition comprising magnetic nanoparticles bound to free-radical-producing enzyme to produce a polymer derived from said monomers. 
     
     
         43 . The process of  claim 42 , wherein said monomers are comprised of vinyl-addition monomers. 
     
     
         44 . The process of  claim 42 , wherein said magnetic nanoparticles are comprised of mesoporous aggregates of magnetic nanoparticles, wherein said mesoporous aggregates of magnetic nanoparticles have mesopores in which free-radical-producing enzyme is embedded. 
     
     
         45 . The process of  claim 42 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are surface-coated with gold. 
     
     
         46 . The process of  claim 42 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme reside on the surface of ferromagnetic submicrometric particles having a size of at least 20 nanometers. 
     
     
         47 . The process of  claim 42 , wherein said magnetic nanoparticles bound to free-radical-producing enzyme are captured by magnetic separation after said process and re-used after being captured, wherein said magnetic nanoparticles bound to free-radical-producing enzyme substantially retain their activity after being captured and re-used.