Enzyme immobilization is one of the most common ways to improve the stability of
biocatalyst, which, among other things, allows the reuse of environmentally friendly
biocatalysts. In the last two decades, the preparation of cross-linked enzyme aggregates
(CLEA) has proven to be a very effective, fast, and cost-effective way of immobilization. A
novel process for the preparation of cross-linked enzyme aggregates of selected amine
transaminase (ATA-CLEA) in the microflow system was developed. The mean particle radius
was 37.13 ± 0.38 nm, which is less than in batch process, where particles visible to the neaked
eye are formed. ATA-CLEA particles prepared in microflow process thus showed 87.1 % of
retained activity, which according to literature is 2.4-times more than for CLEA particles
obtained in the batch process. In addition, in-situ separation of the formed aggregates from
the solution was developed and thus eliminating the usual techniques, which in most cases
lead to sticking of the formed particles which lowers retained activity. Instead of
centrifugation, the formed particles in the microflow system were led to a flow membrane
microreactor in which reagents for their formation could be easily removed, and at the same
time the enzyme preparation was immobilized for further biotransformation. The process
with ATA-CLEA particles in the membrane microreactor is more efficient compared to the
non-aggregated enzyme. ATA-CLEA particles are also more stable than non-aggregated
enzymes, as the productivtiy of the membrane microreactor with ATA-CLEA particles was
unchanged for six days of continuous process, while the non-aggregated enzyme’s
productivity fell by 20 % in five days.
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