One-Pot Enzymatic Conversion of Carbon Dioxide and Utilization for Improved Microbial Growth

다국어 초록 (Multilingual Abstract)

<P>We developed a process for one-pot CO<SUB>2</SUB> conversion and utilization based on simple conversion of CO<SUB>2</SUB> to bicarbonate at ambient temperature with no energy input, by using the cross-linking-based composites of carboxylated polyaniline nanofibers (cPANFs) and carbonic anhydrase. Carbonic anhydrase was immobilized on cPANFs via the approach of magnetically separable enzyme precipitate coatings (Mag-EPC), which consists of covalent enzyme attachment, enzyme precipitation, and cross-linking with amine-functionalized magnetic nanoparticles. Mag-EPC showed a half-life of 236 days under shaking, even resistance to 70% ethanol sterilization, and recyclability via facile magnetic separation. For one-pot CO<SUB>2</SUB> conversion and utilization, Mag-EPC was used to accelerate the growth of microalga by supplying bicarbonate from CO<SUB>2</SUB>, representing 1.8-fold increase of cell concentration when compared to the control sample. After two repeated uses via simple magnetic separation, the cell concentration with Mag-EPC was maintained as high as the first cycle. This one-pot CO<SUB>2</SUB> conversion and utilization is an alternative as well as complementary process to adsorption-based CO<SUB>2</SUB> capture and storage as an environmentally friendly approach, demanding no energy input based on the effective action of the stabilized enzyme system.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2015/esthag.2015.49.issue-7/es505143f/production/images/medium/es-2014-05143f_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es505143f'>ACS Electronic Supporting Info</A></P>