| An Enzyme-Nanofiber Composite for Stable and Continuous Long-Term Enzymatic Reaction | ||
| Byoung-In Sang1, Jin Hyung Lee2, Ee Taek Hwang3, Byoung Chan Kim2, Sun-Mi Lee1, Jungbae Kim4 and Man Bock Gu5, (1)Center for Environmental Technology Research, Korea Institute of Science and Technology, Seoul, South Korea, (2)Advanced Environmental Monitoring Research Center (ADEMRC), Gwangju Institute of Science and Technology (GIST), 1, Oryoung-dong, Puk-Gu, Gwangju, South Korea, (3)College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea, (4)Pacific Northwest National Laboratory, 902 Battelle Blvd., PO Box 999, Mailstop K8-93, Richland, WA 99352, (5)Department of Biotechnology, Korea University, Seoul, South Korea For long-term stable operation of enzymatic degradation process, this study shows the preparation and application of enzyme–nanofiber composites, which were prepared by coating an enzyme aggregate, the esterase from Rhizopus oryzae, on the surface of the nanofibers. After immobilization on the nanofiber, the apparent Km for the immobilized esterase was 1.48-fold higher than that of the free esterase, with values of 0.98 and 1.35 mM for the free and immobilized enzymes, respectively. The activity of enzymes in enzyme–nanofiber was very stable, even when the fibers were shaken in glass vials, preserving 80% of the initial activity for 100 days. In addition, the enzyme–nanofiber composite was used repeatedly in 30 cycles of substrate hydrolysis and still remained active. Consequently, the esterase–nanofiber composite was employed within a continuous reactor system to evaluate its use in a long-term and stable continuous substrate hydrolysis reaction. It was found that the production of p-nitrophenol was stable for at least 400 h. This study demonstrates that the enzyme–nanofiber composite can be used in both repeated-batch mode and a continuous mode for a long-term stable operation. Extended Abstract Status: Not Uploaded | ||