Thiol-ene coupling chemistry for immobilization of biocatalysts
The present invention generally relates to immobilized biocatalysts or immobilized enzymes for use in carbon capture and sequestration technology. Thiol-ene chemistry is used to couple a biocatalyst, particularly carbonic anhydrase, to a substrate including a substrate, a solid support, a microparticle, a nanoparticle, or a combination thereof.
1. An immobilized biocatalyst comprising
a substrate; and
a biocatalyst linked to the substrate through a linking moiety comprising a C 1 to C 30 alkylene wherein at least one of the —CH 2 — groups of the alkylene group is replaced by —S—; and optionally, each of one or more of the other —CH 2 — groups of the alkylene group is independently replaced by —(CH 2 —CH 2 —O) x —, —O—, —C(O)—, —NR 3 —, —Si(OR 1 )(OR 2 )—, —Si(R 5 )(OR 2 )—, —Si(Cl)(Cl)—, arylene, cycloalkylene, heteroarylene, or heterocyclo; or optionally, each of one or more of the other —CH 2 — groups of the alkylene group is independently substituted with a —OH, —NR 3 R 4 , or —C(O)OH, wherein x is an integer from 4 to 2300, R 1 and R 2 are independently hydrogen, alkyl, or another silicon atom attached to the substrate through an —O— group, R 3 and R 4 are independently hydrogen, alkyl, or —CHO, and R 5 is alkyl;
wherein the biocatalyst catalyzes hydration of carbon dioxide.
2. The immobilized biocatalyst of claim 1 wherein the linking moiety comprises a C 1 to C 20 alkylene wherein at least one of the —CH 2 — groups of the alkylene group is replaced by —S—, and optionally, each of one or more of the other —CH 2 — groups of the alkylene group is independently replaced by —(CH 2 —CH 2 —O) x —, —O—, —C(O)—, —NR 3 —, or —Si(OR 1 )(OR 2 )—, and each of one or more of the other —CH 2 — groups of the alkylene group is independently substituted with a —OH, or —C(O)OH, wherein x is an integer from 4 to 2300, R 1 and R 2 are independently hydrogen, methyl, or another silicon atom attached to the substrate through an —O— group, and R 3 is hydrogen.
3. The immobilized biocatalyst of claim 1 wherein the linking moiety comprises a C 1 to C 20 alkylene wherein at least one of the —CH 2 — groups of the alkylene group is replaced by —S—, and each of one or more of the other —CH 2 — groups of the alkylene group is independently replaced by —(CH 2 —CH 2 —O) x —, —O—, —C(O)—, —NR 3 —, or —Si(OR 1 )(OR 2 )—, and each of one or more of the other —CH 2 — groups of the alkylene group is independently substituted with a —C(O)OH, wherein x is an integer from 4 to 2300, R 1 and R 2 are independently hydrogen, methyl, or another silicon atom attached to the substrate through an —O— group, and R 3 is hydrogen.
4. The immobilized biocatalyst of claim 1 wherein the substrate comprises a solid support.
5. The immobilized biocatalyst of claim 4 wherein the substrate is a ceramic, a silicate, alumina, stainless steel, titania, or a combination thereof.
6. The immobilized biocatalyst of claim 5 wherein the substrate comprises microparticles.
7. The immobilized biocatalyst of claim 6 wherein the biocatalyst comprises carbonic anhydrase.
8. The immobilized biocatalyst of claim 5 wherein the substrate comprises nanoparticles.
9. The immobilized biocatalyst of claim 8 wherein the biocatalyst comprises carbonic anhydrase.
10. The immobilized biocatalyst of claim 1 wherein the biocatalyst comprises carbonic anhydrase.
11. The immobilized biocatalyst of claim 10 wherein the carbonic anhydrase comprises a cytosolic carbonic anhydrase, a mitochondrial carbonic anhydrase, a secreted carbonic anhydrase, or a membrane-associated carbonic anhydrase.
12. The immobilized biocatalyst of claim 11 wherein the carbonic anhydrase comprises a mammalian carbonic anhydrase, a plant carbonic anhydrase, or a microbial carbonic anhydrase.
13. The immobilized biocatalyst of claim 2 wherein the biocatalyst comprises carbonic anhydrase.
14. The immobilized biocatalyst of claim 3 wherein the biocatalyst comprises carbonic anhydrase.
15. 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 biocatalysts of claim 10 , the biocatalyst or enzyme being carbonic anhydrase and the carbonic anhydrase being capable of catalyzing hydration of CO 2 into hydrogen ions and bicarbonate ions.
16. The system of claim 15 wherein the substrate comprises microparticles.
17. The system of claim 15 wherein the substrate comprises nanoparticles.
18. A process for removing CO 2 from a CO 2 -containing gas, the process comprising
contacting a gas comprising CO 2 with a water-containing liquid and an immobilized biocatalyst of claim 10 to catalyze hydration of the CO 2 with water and form hydrogen ions and bicarbonate ions.
19. The process of claim 18 wherein the water-containing liquid is an aqueous solution.
20. The process of claim 19 wherein the substrate comprises microparticles.
21. The process of claim 19 wherein the substrate comprises nanoparticles.