POLYSILICATE-POLYSILICONE ENZYME IMMOBILIZATION MATERIALS
The present invention generally relates to improvements in enzyme immobilization, particularly for use in the field of carbon dioxide capture and sequestering. It has been discovered that the utilization of sol-gel processes to immobilize enzymes in polysilicate-polysilicone copolymer coatings and particles, and the deposition of these coatings on solid state supports or use of suspensions of these particles, provides significant benefits for use in industrial applications involving enzymatic catalysts.
1 .- 97 . (canceled)
98 . An immobilized enzyme comprising
an enzyme; and
an immobilization material;
wherein the enzyme is entrapped within the immobilization material and the immobilization material is derived from reaction of a sol, the sol comprising (i) an alkoxy silane or an organotrialkoxy silane or metasilicate, (ii) a poly(silicone), and (iii) an enzyme.
99 . The immobilized enzyme of claim 98 wherein the poly(silicone) comprises a poly(siloxane).
100 . The immobilized enzyme of claim 98 wherein the sol further comprises a hydrophilic additive.
101 . The immobilized enzyme of claim 100 wherein the sol further reacts with a catalyst.
102 . The immobilized enzyme of claim 98 wherein the enzyme comprises a lipase, a glucose isomerase, a nitrilase, a glucose oxidase, a protease, a carbonic anhydrase, a pepsin, an amylase, a fungal amylase, a maltogenic amylase, a cellulase, a lactase, an esterase, a carbohydrase, a hemicellulase, a pentosanase, a xylanase, a pullulanase, a β-glucanase, an acetolactate decarboxylase, a β-glucosidase, a glutaminase, a penicillin acylase, a chloroperoxidase, an aspartic β-decarboxylase, a cyclodextrin glycosyltransferase, a subtilisin, an aminoacylase, an alcohol dehydrogenase, an amino acid oxidase, a phospholipase, a urease, a cholesterase, a desulfinase, a lignin peroxidase, a pectinase, an oxidoreductase, a dextranase, a glucosidase, a galactosidase, a glucoamylase, a maltase, a sucrase, an invertase, a naringanase, a bromelain, a ficin, a papain, a pepsin, a peptidase, a chymosin, a thermolysin, a trypsin, a triglyceridase, a pregastric esterase, a phosphatase, a phytase, an amidase, a glutaminase, a lysozyme, a catalase, a dehydrogenase, a peroxidase, a lyase, a fumarase, a histadase, an aminotransferase, a ligase, a cyclase, a racemase, a mutase, an oxidase, a reductase, a ligninase, a laccase, a chloroperoxidase, a haloperoxidase, a hydrogenase, a nitrogenase, an oxynitrilase, or a combination thereof.
103 . The immobilized enzyme of claim 102 wherein the enzyme is a carbonic anhydrase.
104 . The immobilized enzyme of claim 101 wherein the enzyme is a carbonic anhydrase.
105 . The immobilized enzyme of claim 98 wherein the alkoxy silane is tetramethylorthosilicate, tetraethylorthosilicate, methyltriethylorthosilicate, ethyltrimethylorthosilicate, dimethyldiethylorthosilicate, tetraglyceryl silicate, or a combination thereof.
106 . The immobilized enzyme of claim 98 wherein the organotrialkoxy silane is trimethoxymethylsilane, trimethoxyethylsilane, or a combination thereof.
107 . The immobilized enzyme of claim 98 wherein the alkoxy silane comprises tetramethylorthosilicate.
108 . The immobilized enzyme of claim 98 wherein the poly(silicone) is a poly(siloxane) selected from the group consisting of poly(dimethylsiloxane), poly(dimethylsiloxane)-co-poly(alkene oxide), or a combination thereof.
109 . The immobilized enzyme of claim 108 wherein the poly(siloxane) comprises poly(dimethylsiloxane).
110 . The immobilized enzyme of claim 108 wherein the poly(silicone) is silanol-terminated.
111 . The immobilized enzyme of claim 100 wherein the hydrophilic additive is poly(vinyl alcohol), poly(ethylene oxide), a quaternary ammonium polymer, a crown ether, a cyclodextrin, a surfactant, hexadecyltrimethylammonium bromide, poly(1-methyl-4-vinylpyridinium bromide), poly(acrylamide-methacryloxyethyltrimethylammonium bromide), or a combination thereof.
112 . The immobilized enzyme of claim 111 wherein the crown ether is 12-crown-4, 1,7-diaza-12-crown-4, 1,4,8,11-tetrathiacyclotetradecane, 1,4,8,12-tetraazacyclopentadecane, 15-crown-5,18-crown-6, dibenzo-18-crown-6, dicyclohexano-18-crown-6, (18-crown-6)-2,3,11,12-tetracarboxylic acid, 1-aza-18-crown-6, diaza-18-crown-6, or a combination thereof.
113 . The immobilized enzyme of claim 112 wherein the crown ether comprises 18-crown-6.
114 . The immobilized enzyme of claim 100 wherein the alkoxy silane comprises tetramethylorthosilicate, the poly(siloxane) comprises polydimethylsiloxane, and the hydrophilic additive comprises a crown ether.
115 . The immobilized enzyme of claim 98 wherein the molar ratio of alkoxy silane or organotrialkoxy silane or metasilicate to poly(silicone) is from about 2:1 to about 8:1.
116 . A process for removing CO 2 from a CO 2 -containing gas, the process comprising
contacting a liquid with a CO 2 -containing gas; and contacting the CO 2 in the liquid with the immobilized enzyme of claim 104 to catalyze hydration of the CO 2 and form a treated liquid comprising hydrogen ions and bicarbonate ions.
117 . A system for removing CO 2 from a CO 2 -containing gas comprising a reaction vessel comprising a bottom portion containing a gas inlet and a liquid outlet, a top portion containing a liquid inlet and a gas outlet, and a middle portion containing a plurality of the immobilized enzymes of claim 103 , the carbonic anhydrase being capable of catalyzing hydration of CO 2 into hydrogen ions and bicarbonate ions.