(439e) Highly Efficient Enzyme Immobilization and Stabilization within Meso-Structured Onion-Like Silica for Biodiesel Production

Highly Efficient Enzyme Immobilization
and Stabilization within Meso-Structured Onion-like Silica
for Biodiesel Production

Seung-Hyun
Jun, Jinwoo Lee, Taeghwan
Hyeon, and Jungbae Kim*

Department
of Chemical and Biological Engineering, Korea University, Seoul, Korea

Advanced
Functional Nanomaterials Laboratory, Department of Chemical Engineering, Pohang
University of Science and Technology, Pohang, Kyungbuk
790-784, Korea

National
Creative Research Initiative Center for Oxide Nanocrystalline
Materials and School of Chemical Engineering, Seoul National University, Seoul
151-744, Korea

Abstract

Enzyme was immobilized and stabilized
in meso-structured onion-like silica (Meso-Onion-S), which has highly-curved meso-pores
of 10 nm diameter in a multi-shell structure in a form of nanoscale enzyme
reactors (NERs). NERs were prepared via a two-step process of enzyme adsorption
and subsequent enzyme crosslinking, which effectively prevents the leaching of
crosslinked enzyme aggregates from highly-curved mesopores of Meso-Onion-S. As a result, NERs in Meso-Onion-S
significantly improved the enzyme stability as well as the enzyme loading. For
example, NER of lipase (NER-LP) was stable under rigorous shaking for 40 days,
while the control sample of adsorbed LP (ADS-LP) with no enzyme crosslinking
showed a rapid inactivation due to rigorous enzyme leaching under shaking.
Stable NER-LP was successfully employed to produce biodiesels, fatty acid
methyl esters, from the LP-catalyzed transesterification of soybean oil with methanol.
Interestingly, the specific activity of NER-LP was 23 and 10 times higher than
those of free LP and ADS-LP, respectively, revealing the importance of LP
stabilization in the form of NER-LP in the presence of organic solvents.