(372b) From Racemate to Single Enantiomer with 100% YIELD

Integration of SMB enantioseparation
and mild enzymatic racemization allows for obtaining
the target enantiomer from the racemic
mixture in theoretically 100% yield- compared to 50% yield with a stand-alone chiral SMB [1].

Next, such a process gives access to both enantiomers with one SMB installation and one enzyme
compared to the three enzymes required in dynamic kinetic resolution approaches
for the same flexibility.

In this work we present the design and
operation of an integrated process realized by coupling of an SMB equipped with
Chirobiotic TAG (Sigma Aldrich, USA) columns [2], a nanofiltration
concentration deviceand an enzyme membrane reactor containing an amino acid
racemase for the production of enantiopure amino acids, specifically D-methionine (Fig.1).

However, due to the direct coupling the
same solvent needs to be applied in all unit operations. Hence, the design and
optimization of a fully integrated production system require a detailed
characterization and accurate parameterization of all involved units with
respect to potentially inter-operable solvent compositions, specifically
reaction kinetics and stability, adsorption isotherms and rejection of the nanofiltration membrane. Based on these parameters model-based
design is applied in order to identify appropriate operating points for aset of specifications such as product purity. The
usefulness of the obtained design is evaluated by experimental runs of the
fully integrated process. This constitutes the first report on the experimental
implementation of integration of chiral SMB and
enzymatic racemization.

References

1) M. Bechtold, S. Makart,
M. Heinemann, S. Panke, Journal of Biotechnology 124 (2006) 146

2) M.Fuereder, S.Panke, M.Bechtold, Journal of
Chromatography 1236 (2012), 123