Abstract
Biological systems are the excellent functional systems, which includes sensing, morphological change, synthesis and conversion. Those inspire to create biomimetic artificial systems. In biological systems, compounds were synthesized by multistep enzymatic conversions, which its efficiency cannot be reproduced in bulk chemical reaction. Here we show that efficient multistep enzymatic reaction can be achieved within microreaction system. We describe preparation of enzyme-immobilized tandem microcapillary reactor, then show the performance of this tandem microreactor which mimics high efficiency of multistep enzyme reaction in biological systems.We have chosen three step enzymatic conversion reaction of citric acid into L-lactic acid as a model case. First, we prepared three enzyme immobilized microreactors, which immobilize citrate lyase, oxalacetic acid decarboxylase, and L-lactic dehydrogenase, respectively. The enzymes were immobilized by sol-gel surface modification method. Resulting microreactors were connected in tandem, to perform multistep reactions. Reaction was performed by loading a 100 mM solution of sodium citrate buffer (pH7.4) by pumping, and evaluated by HPLC analysis of the product. The microreactor could convert citrate into L-lactate even at a flow rate of 10 ml/min. This result demonstrates that our microreactor can perform multistep reaction efficiently.
