Carbonic anhydrases (CAs) are enzymes that can function at physiologic interfaces and catalyze the interfacial conversion of carbon dioxide (CO2) into bicarbonate (HCO3-) with an extraordinarily high catalytic efficiency. Even though CAs have potential to be used for CO2 sequestration, significant mass transfer resistance and poor enzyme stability at gas-liquid interface often limit the effectiveness of the enzyme. Here, we report a density-adjustable 3D-printed platform, which can accommodate electrospun polymer fibers with immobilized CA and enable the positioning of immobilized CA in an air-water biphasic system. By using 3D printing, we fabricate interfacial devices consisting of two floating units and different number of biocatalytic units. Two mesh structures of each biocatalytic unit are used to sandwich immobilized CA while two floating units, connected on either side of the biocatalytic units, have an internal hollow volume that enables controlling the position of the enzyme-loaded interfacial device at or near the air-water interface. The positioning of interfacial device directly at the biphasic interface accelerated CO2 conversion by 1.8- and 3.4-fold when compared to reactions performed with immobilized CA within the aqueous solution and a control interfacial device without immobilized CA, respectively. The CA-loaded interfacial device retained 99.3 % and 88.2 % of its initial CO2 conversion rate after ten recycles and after subsequent storage in an aqueous buffer at 4 °C for 459 days, respectively. Facile combination of interfacial devices and immobilized enzymes on polymer fibers has paved the way to practical uses of biocatalysts for interfacial CO2 sequestration.
Bibliographical noteFunding Information:
This work was supported by the Global Research Laboratory Program ( 2014K1A1A2043032 ) through the National Research Foundation of Korea (NRF) grants funded by the Korea government Ministry of Science and ICT (MSIT) . This work was also supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20142020200980 & No. 20182010600430 ).
© 2020 Elsevier Ltd.
- 3D printing
- CO conversion and utilization
- Carbonic anhydrase
- Enzyme immobilization
- Interfacial biocatalysis
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Waste Management and Disposal
- Process Chemistry and Technology