Journal of Separation Science
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Impact Factor: 2.591
ISI Journal Citation Reports © Ranking: 2012: 25/75 (Chemistry Analytical)
Online ISSN: 1615-9314
September 13, 2007
Development of a silica monolith micro-bioreactor entrapping highly activated lipase and an experiment toward integration with chromatographic separation of chiral esters
Micro-bioreactors are effective for high-throughput production of expensive products from small amounts of substrates. Lipases are versatile enzymes for chiral syntheses, and are highly activated when immobilized in alkyl-substituted silicates by the sol-gel method. For practical application of sol-gel immobilized lipases to a flow system, a micro-bioreactor loaded with a macroporous silica monolith is well suited, because it can be easily integrated with a chromatographic separator for optical resolution. The team of Koei Kawakami attempted to develop a micro-bioreactor containing a silica monolith-immobilized lipase. A non-shrinkable silica monolith was first formed from a 4:1 mixture of methyltrimethoxysilane (MTMS) and tetramethoxysilane (TMOS). It was then coated with silica precipitates entrapping lipase, derived from a 4:1 mixture of n-butyltrimethoxysilane (BTMS) and TMOS. As a result, monolith treated with the BTMS-based silicate entrapping lipase exhibited approximately ten times higher activity than non-treated monolith-immobilized lipase derived from the MTMS-based silicate, in transesterification between glycidol and vinyl n-butyrate in isooctane. A commercially available chiral column was connected in series to the monolith micro-bioreactor, and a pulse of substrate solution was supplied at the inlet of the reactor. Successful resolution of racemic ester produced was achieved in the chromatographic column.
To appear in Issue 17/2007:
K. Kawakami, D. Abe, T. Urakawa, A. Kawashima, Y. Oda, R. Takahashi, S. Sakai, J. Sep. Sci. 2007, 30 (17).