Premium
Enzymatic synthesis of chiral amino‐alcohols by coupling transketolase and transaminase‐catalyzed reactions in a cascading continuous‐flow microreactor system
Author(s) -
Gruber Pia,
Carvalho Filipe,
Marques Marco P. C.,
O'Sullivan Brian,
Subrizi Fabiana,
Dobrijevic Dragana,
Ward John,
Hailes Helen C.,
Fernandes Pedro,
Wohlgemuth Roland,
Baganz Frank,
Szita Nicolas
Publication year - 2018
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26470
Subject(s) - microreactor , transketolase , chemistry , biocatalysis , catalysis , combinatorial chemistry , transaminase , flow chemistry , enzyme catalysis , cascade reaction , organic chemistry , enzyme , reaction mechanism
Rapid biocatalytic process development and intensification continues to be challenging with currently available methods. Chiral amino‐alcohols are of particular interest as they represent key industrial synthons for the production of complex molecules and optically pure pharmaceuticals. (2 S ,3 R )‐2‐amino‐1,3,4‐butanetriol (ABT), a building block for the synthesis of protease inhibitors and detoxifying agents, can be synthesized from simple, non‐chiral starting materials, by coupling a transketolase‐ and a transaminase‐catalyzed reaction. However, until today, full conversion has not been shown and, typically, long reaction times are reported, making process modifications and improvement challenging. In this contribution, we present a novel microreactor‐based approach based on free enzymes, and we report for the first time full conversion of ABT in a coupled enzyme cascade for both batch and continuous‐flow systems. Using the compartmentalization of the reactions afforded by the microreactor cascade, we overcame inhibitory effects, increased the activity per unit volume, and optimized individual reaction conditions. The transketolase‐catalyzed reaction was completed in under 10 min with a volumetric activity of 3.25 U ml −1 . Following optimization of the transaminase‐catalyzed reaction, a volumetric activity of 10.8 U ml −1 was attained which led to full conversion of the coupled reaction in 2 hr. The presented approach illustrates how continuous‐flow microreactors can be applied for the design and optimization of biocatalytic processes.