Leucine dehydrogenase (LeuDH) has emerged as the most promising biocatalyst for L-
tert-leucine (L-Tle) production via asymmetric reduction in trimethylpyruvate (TMP). In this study, a new LeuDH named
PbLeuDH from marine
Pseudomonas balearica was heterologously over-expressed in
Escherichia coli, followed
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Leucine dehydrogenase (LeuDH) has emerged as the most promising biocatalyst for L-
tert-leucine (L-Tle) production via asymmetric reduction in trimethylpyruvate (TMP). In this study, a new LeuDH named
PbLeuDH from marine
Pseudomonas balearica was heterologously over-expressed in
Escherichia coli, followed by purification and characterization.
PbLeuDH possessed a broad substrate scope, displaying activities toward numerous L-amino acids and
α-keto acids. Notably, compared with those reported LeuDHs,
PbLeuDH exhibited excellent catalytic efficiency for TMP with a
Km value of 4.92 mM and a
kcat/
Km value of 24.49 s
−1 mM
−1. Subsequently, L-Tle efficient production was implemented from TMP by whole-cell biocatalysis using recombinant
E. coli as a catalyst, which co-expressed
PbLeuDH and glucose dehydrogenase (GDH). Ultimately, using a fed-batch feeding strategy, 273 mM (35.8 g L
−1) L-Tle was achieved with a 96.1% yield and 2.39 g L
−1 h
−1 productivity. In summary, our research provides a competitive biocatalyst for L-Tle green biosynthesis and lays a solid foundation for the realization of large-scale L-Tle industrial production.
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