Industrial Biotransformations

l-Hydantoinase
Arthrobacter sp. DSM 9771
● Processes for the production of L-amino acids are still limited. Therefore Degussa developed a
tailor-made recombinant whole cell biocatalyst. Further reduction of biocatalyst cost by use of
recombinant Escherichia coli cells overexpressing a hydantoinase, carbamoylase and hydantoin
racemase from Arthrobacter sp. DSM 9771 were achieved.
● This highly active recombinant whole-cell biocatalyst can be produced in high-cell density fermentation
on a m 3 -scale at concentrations above 50 g · L –1 dry cell weight.
● Although the l-selectivity of the designed enzyme is not impressive and leaves room for
further improvements, the productivity of the process can be dramatically improved. These
improvements have been confirmed on a m 3 -scale using a simple batch reactor concept
coupled to a continuous centrifuge for cell separation.
Fig. 3.5.2.4 – 2
3) Flow scheme
Not published.
4) Process parameters
conversion: 40 %
yield: 100 %
ee: 20 %
reactor type: batch
reactor volume: m3 down stream processing: continuously operated centrifuge for cell separation
company: Degussa AG, Germany
5) Product application
● Optically pure natural and non-natural l-amino acids.
418
O
NH 2
OH
O
NH 2
L-2-Aminobutyric acid L-Norleucine L-3-(3'-Pyridyl)-alanine
S
O
NH 2
OH
EC 3.5.2.4
Examples of natural and nonnatural L-amino acids available from the L-hydantoinase technology
OH
L-Methionine L-Tryptophane
N
O
NH 2
N
OH
O
NH 2
OH