A miniaturized packed bed reactor (MPBR) applying LentiKats (R) with immobilized co-transaminase was developed as a tool for continuous enzymatic process establishment. A systematic increase in reactor capacity was achieved by increasing individual dimensions of the rectangular and hexagonal channels, where lens-shaped polyvinyl alcohol particles were either uniformly or randomly distributed. Evaluation of reactors with volumes ranging from a few mu L up to several mL revealed the benefit of using a single layer of particles packed between two plates forming a wide channel with triangular inlet and outlet parts containing pillars, where very high production rates and biocatalyst accessibility were achieved. MPBR was also used to establish temperature dependence of the immobilized co-transaminase yielding 55 degrees C as an optimal temperature. More than 80% of the initial productivity was retained after 21 days of continuous operation of the MPBR at 24 degrees C, suggesting a high operational stability. The miniaturized reactor developed in this study was found to be very efficient for omega-transaminases-catalyzed chiral amine process development. (C) 2016 Elsevier Ltd. All rights reserved.