Immobilization of His$_6$-tagged amine transaminases in microreactors using functionalized nonwoven nanofiber membranes

Abstract

Enzyme immobilization is one of the essential tools that enables bioprocess intensification as it facilitates reuse of enzyme. Nanomaterials can be used as supports for enzyme immobilization because of their high surface to volume ratio. In his work a designed biocompatible non-woven nanofiber was used as a support for hexahistidine tagged amine transaminase immobilization in a microreactor. Four different nanofibers were tested and the one with surface immobilized Cu$^{2+}$ ions was proven to be the best. Additionally, direct immobilization of overexpressed enzymes in E. coli cell lysate was performed and yielded loads up to 1088 U mL$^{-1}$. The highest turnover number reached within the indicated time was 7.23 10$^6$